Nanjing University of Aeronautics and Astronautics, China
Research Organization for Information Science and Technology, Japan
National Institute for Materials Science (NIMS), Japan
Oreste De Luca
Università della Calabria, Italy
Shanghai Jiao Tong University, China
Karlsruhe University of Applied Sciences, Germany
Ipsita A. Banerjee
Fordham University, United States
Imperial College London, United Kingdom
BOKU - University of Natural Resources and Life Sciences, Austria
Dennis G. Drescher
Wayne State University, United States
University of Victoria, Canada
Tohoku University, Japan
The First Affiliated Hospital of Chongqing Medical University, China
Tomás Barbosa da Costa
Federal University of São João del-Rei, Brazil
Maria J. Ramalho
University of Porto, Portugal
University of Miskolc, Hungary
Sérgio S. Camargo Jr
Federal University of Rio de Janeiro, Brazil
Wrocław University of Science and Technology, Poland
Toyota Research Institute of North America, United States
Surya R. Kalidindi
Georgia Institute of Technology, United States
Ran Y. Suckeveriene
Kinneret Academic College on the Sea of Galilee, Israel
Brandon J. Teffta
Medical College of Wisconsin & Marquette University, United States
Sungkyunkwan University, South Korea
Shanxi Medical University, China
National Cheng Kung University, Taiwan
Akamu Jude Ewunkem
Winston Salem State University, United States
Luis Alfonso Garcia Cerda
Research Centre of Applied Chemistry, Mexico
University of Moratuwa, Sri Lanka
University of Leipzig, Germany
Tokyo Institute of Technology, Japan
Jian Qiang Liu
Jiujiang University, China
National Institute of Chemistry Ljubljana, Slovenia
Univ. Florence, Italy
Wouter Claassen Witteveen+Bos, Netherlands
The future of bio-based bridges
The Dutch government's climate ambitions, its position on themes such as circularity and sustainability and the EU's action plan Bio-Economy Strategy, have played an important role in the switch to alternative materials, such as bio-based composites.
This already has led to the ﬁrst bio-based composite movable bridge that has been built in 2020 in Ritsumasyl, The Netherlands. The realized construction has an overall length of 66 meter. The first half is fixed and the second consists of an asymmetrical moveable swing part with a free main span of 22 meters and a counterweight section of 12 meters. The bridge deck is made of around 85% bio-based material with a service life of 50 years. The bridge is built under vacuum injection with Amplitex flax fibres made by Bcomp and an Epoxy resin 1800 ECO + 1804 ECO made by Resoltech. In the deck a balsa wooden core is used for distribution of the local loads.
Together with universities we our now working on three more bio-based bridges (one in Ulm Germany and two in Bergen op Zoom, The Netherlands). In these new bridges, the epoxy is replaced by a much more affordable bio-polyester resin to make these bridges a compatible alternative. This resin gives new challenges due to the permeability.
To understand the behavior, all those bio-based bridges are foreseen with sensor technology combined with smart computer algorithms. This is known as Structural Health Monitoring. A smart sensor system evaluates sensor input and generates early warnings, before critical levels of material degradation are reached. It enables real time maintenance or replacement of components.
These innovative bridge designs shows the possible applications of bio-composites in civil constructions. The ultimate future goal is to actually build these bridge with natural fibers and a 100% bio-based resin, a completely circular alternative material.
Michiko Yoshitake National Institute for Materials Science, Japan
Title: Interdisciplinary utilization of scientific principles for materials R&D: Materials Curation®
Materials properties are inter-related in complicated ways, which makes finding materials with desired properties difficult. Quite recently, machine learning techniques has attracted attention to predict a target property using large numerical dataset. Even autonomous experimentation where the optimization of experimental parameters with machine learning has been developed (middle bule circle in Fig. 1).
However, the use of numerical dataset means that one should determine a search area of materials (such as nitrides, perovskites, imides) at the first step, which makes materials search narrow. Historically, innovative materials have been discovered outside of commonly searched materials. Therefore, a tool to widen humans thinking is desired. We have developed such tool to support researchers thinking (left red circle in Fig.1), which is a database and search system of materials property relationship. In Fig.2, a concept of the tool is shown (patented internationally).
The concept in Fig. 2 has been implemented as a software by collaborating with a company. Figure 3 shows a screenshot of the software, which shows how thermal conductivity and electrical conductivity are inter-related with many other properties. In the presentation, the software will be demonstrated.
Jorge David López Gutiérrez Toluca Institute of Technology, Mexico
Nanoparticle detection on SEM images using a neural network and semi-synthetic training data
In materials science, the use of scanning electron microscopy (SEM) is a valuable aid in the process of characterizing material samples, the processing of the images produces by this technique often involves the use of general purpose image manipulation software or case-specific image processing techniques to carry out tasks such as nanoparticle detection and measurement. In recent years, the use of networks has been successfully implemented to detect and classify electron microscopy images as well as the objects within them.
In our study, we proposed using two versions of the YOLO neural network architectures1 to train a series of models intended to detect cubical and quasi-spherical nanoparticles (NP) in SEM images that could serve as the basis of a software capable of performing the characterization of NPs on this type of images. The detection models were trained on a couple of datasets composed of a combination of real SEM images, mainly from the repository by Aversa et al.2, and synthetic ones generated by a semi-arbitrary method that uses images from our own repository as a source.
The proposed methodology yielded four models were tested a dataset made up of images of silver (Ag) and hydroxyapatite (HA) nanoparticles, obtaining promising results measured by median average precision (mAP) and Jaccard coefficient. The best performing detector, based on YOLOv4-tiny and trained with and unbalanced dataset, achieved a 77.68% of correctly detected NPs after 140,000 epochs; proving it capable of detecting objects in images different from the ones used for training. These results can be improved through the increase of training data as well as longer training sessions.
Victor Hugo Mendez-Garcia Autonomous University of San Luis Potosí, Mexico
Novel THz emitters based in MBE grown hyperbolic-tan In graded metamorphic films.
The increasing and incessant requirements for both fast and vast quantity of information exchange have forced worldwide researchers to the development of new technologies that may allow to acquire the information at nearly-instantaneous access. In this direction, THz technologies have been envisioned with the potential to provide new devices working at ultra-high-speed communication in the near future, and to achieve this goal innovative THz radiation emitters are demanded. In this work, novel THz emitters based on InGaAs/GaAs alloys grown at gradual steps of In concentration by the molecular beam epitaxy (MBE) technique are presented. These devices exhibit higher emission compared to those emitters based on photo-conductive antennas. The two main effects responsible for the emission are the ballistic transport of the carriers which acquire the kinetic energy from the energy difference between the excitation radiation and the band-gap, and the second effect is the acceleration of the electrons, which is improved by the modification of the surface electric field caused by the band-bending in the metamorphic layer. To assure the ballistic transport it was important to maintain high crystalline quality throughout the growth of the layer, and it implies having a low density of dislocations, which is not an easy task considering the 7% mismatch between the materials InAs and GaAs. To prompt the acceleration of carriers, we propose here novel designs on the emitter structure comprises concave and convex concentration profiles. We observe that the emission of these novel devices is twice higher than the conventional GaAs THz emitters.
Paul C. DeRose National Institute of Standards and Technology (NIST), Gaithersburg, USA
Certified reference materials for number concentration of submicrometer particles
The number of commercially available instruments for measuring number concentrations and size distributions of submicrometer particles has recently increased, inspiring greater interest in a wide variety of areas in science, technology, engineering and medicine (STEM). These include (1) virus and bioparticle counting for clinical applications, (2) on-line water bioburden analysis (OWBA) in biopharmaceuticals, (3) aggregate and insoluble particulate quantitation for protein drug and biotherapeutic efficacy, (4) particle number concentrations for ultrapure water and chemical solutions in semiconductor manufacturing, and (5) toxicological and ecotoxicological risks of nanoparticles from commercial products. Submicrometer particle standards are needed to improve the accuracy and reproducibility of these techniques. The number concentrations of fluorescently labeled polystyrene submicrometer sphere suspensions with nominal diameters from 100 nm to 500 nm were measured using seven different techniques. Diameter values were also measured where possible. The diameter values were found to agree within 20%, but the number concentration values differed by as much as a factor of two. Accuracy and reproducibility related with the different techniques were compared with the goal of using number concentration standards for instrument calibration. Three of the techniques were used to determine SI-traceable number concentration values. The three independent values were then averaged to give consensus values. This consensus approach is proposed as a protocol for certifying SI-traceable number concentration standards.
Arnab Ganguly Khalifa University, Abu Dhabi , United Arab Emirates
Studies of Magnetic Domains and Magnetization Reversal Mechanism in Nickel Nano-particles
In the last few decades magnetic nanoparticles have attracted a lot of attention to various fields of research such as magnetic memory, catalysis chemistry, targeted drug delivery and magnetic resonance imaging. The processes that involve magnetic nano-particles are highly dependent on the properties of the magnetic unit cell called domains. The chirality of the domain wall has strong influence on the magnetization reversal dynamics[4,5]. Hence, an in depth understanding of the domain walls as a function of shape, size and assembly orientation is of high importance in order to improve the efficiency of the processes.
In our study we prepare nickel nano-particles through chemical route using Hydrazine reduction technique from nickel salt. SEM image of Ni nano-particles and corresponding energy dispersive X-ray (EDX) result are shown in Fig. 1. The particle size is controlled by varying the reaction conditions such as molar ratio of the reagents, reaction temperature and pH level. Monodisperse particles of different size are extracted from the reaction solution with the help of a varying speed centrifuge and a strong bar magnet. As the diameter of the particles deceases surface to volume ratio increases resulting in a stronger surface anisotropy than volume anisotropy. Thus, for smaller size particles surface plays a predominant role in defining the domains and its reversal dynamics. In our study we visualize as well as characterize of the domain wall spin structures using Lorentz TEM. The reversal mechanism is studied using MOKE and SQUID technique. The domain wall dynamics are analyzed using Mumax3 simulator while the Lorentz TEM data is characterized using Matlab. The study uncovers the role of underlying energy parameters contributing to the domain wall dynamics.
Gobind Das Khalifa University, United Arab Emirates
Competition between chiral energy and chiral damping in the asymmetric expansion of magnetic bubbles
Magnetic bubbles are considered as promising candidate in data storage and data transfer applications. In recent time, creep motion of magnetic bubbles attracts a considerable attention to research[2,3] due to its intrigue dynamical behavior which is sensitive to its spin texture. In this study we perform a systematic investigation of magnetic field induced bubble expansion in structural inversion asymmetric multilayers.
Out of plane magnetized film stack of Ta(3nm)/Pt(3 nm)/Co(0.6 nm)/Pt(0 to 1 nm)/IrMn(3 nm) is sputtered on Si substrate. Polar magneto-optic Kerr effect (P-MOKE) microscopy is used for magnetic domain imaging. The bubbles are expanded asymmetrically along the in-plane field combined with an out of plane field. The asymmetry is measured as 2(v_(↓↑)-v_(↑↓))/(v_(↓↑)+v_(↑↓))) where, v_(↓↑) and v_(↑↓) corresponds to the opposite (↓↑ and ↑↓) domain walls velocity. We study the asymmetry as a function of in plane and out of plane field constant. When the Pt layer thickness on top of Co is varied from 0 to 1 nm the in-plane asymmetry curve changes shape and finally becomes symmetrically opposite as shown in Fig. 1. Interestingly, there exist some intermediate thickness of Pt (0.3 nm) in which the asymmetry can be opposite depending on the magnitude of in-plane field. Further we investigate the out of plane field dependence of domain wall velocity at constant in-plane fields. From this study we conclude that both Dzyaloshinskii-Moriya interaction and chiral damping has a crucial role to play in this system. Result shown in Fig. 1 is explained by a combined effect of these two phenomena. This research shows an effective way of controlling the bubble asymmetry which can be useful for future logic device applications.
Helen M. Chan Lehigh University, United States
Redox Inspired Routes for Fabrication of HEAs and Novel Composites
The extraction of a metallic element via the reduction of oxide ores is long-established. Recently, work by the Lehigh group has shown that the reduction of a multi-oxide mixture is a viable method for the fabrication of so-called high entropy alloys (also known as multi-principal element alloys). These materials have attracted intense research interest due to their potential for enhanced properties versus conventional alloys. To date, the vast majority of the MPEA compositions studied have been prepared by casting of a molten mixture of the elemental metals. A process will be discussed whereby a milled mixture of metal oxide powders is consolidated via die-pressing, and subsequently subjected to a reduction anneal using non-flammable mixtures of hydrogen and argon. The effect of heat-treatment conditions on the microstructural evolution will be discussed for several HEA compositions, including Cantor related alloys. Compared to similar alloys fabricated by melt processing, interesting differences emerge with regard to the composition and distribution of the phases. Significantly, the presence of alloying elements can lead to enhanced reduction in certain oxides, i.e. the oxide may be successfully reduced to the metallic state under conditions where the single oxide would not. The reasons underlying this synergistic effect will be discussed, as well as the potential advantages of the ceramic derived process.
In a similar vein, recent work has also shown that the partial reduction of complex oxides of the type MIMIIOx+y can give rise to unique microstructures, comprising interpenetrating mixtures of metallic and ceramic phases. Examples of ceramics which have been shown to be amenable to this approach include CuAlO2 (delafossite) and CoTiO3. The range of microstructures which can be obtained will be presented, as well as a discussion of the reaction mechanisms.
Oumayma M’GHARI Hassan I University - Settat, Morocco
Heat treatment of high manganese austenitic steel: STRUCTURAL AND MECHANICAL PROPERTIES
• Background: Technological progress is based on the development of different types of materials. Among the materials most solicited, we mention metals and alloys. The development of these materials has been initiated and resulted in a wide range of metallic materials, including austenitic manganese constituting, until today, a center of interest of several research works given their wide use in the industry as well as the recent progress by observation and characterization instruments.
• Objective: The aim of the paper is to investigate the heat treatment conditions of high manganese austenitic steel and to determine their influence on the structure and mechanical properties.
• Methods: The samples were subjected to an austenitization treatment at five different temperatures: 980 °C, 1000 °C, 1020 °C, 1040 °C, and 1060 °C for 1 hour. The experimental techniques used are hardness, nanoindentation tests, optical microscopy and X-ray diffraction. Hardness and microhardness measurements were performed to determine the wear behavior of the studied steels.
• Results: The results indicated that the temperature affects the microstructure, by increasing the austenitizing temperature with pronounced growth of the austenite as well as the dissolution of carbides M7C3, the nanohardness and the modulus of elasticity decreases considerably.
• Conclusion: The heat treatment of materials modifying the microstructure is closely related to the mechanical behavior of the austenitic manganese steel. Therefore, the control of structural changes by heat treatment is essential to obtain the desired properties. The established heat treatment conditions of the obtained steel can be suitable for several industrial applications.
Chris Binns Unidad de Biomedicina UCLM-CSIC, Spain
Effectiveness of silver nanoparticles deposited in facemask material for neutralising viruses
Cloth used for facemask material has been coated with silver nanoparticles using an aerosol method that passes pure uncoated nanoparticles through the cloth and deposits them throughout the volume. The particles have been characterized by electron microscopy and have a typical diameter of 4 nm with the atomic structure of pure metallic silver presented as an assortment of single crystals and polycrystals. The particles adhere well to the cloth fibers, and the coating consists of individual nanoparticles at low deposition times, evolving to fully agglomerated assemblies in heavy coatings. The cloth was exposed to Usutu virus and murine norovirus particles in suspension and allowed to dry, following which, the infectious virus particles were rescued by soaking the cloth in culture media. It was found that up to 98% of the virus particles were neutralized by this contact with the silver nanoparticles for optimum deposition conditions. The best performance was obtained with agglomerated films and with polycrystalline nanoparticles. The work indicates that silver nanoparticles embedded in masks can neutralize the majority of virus particles that enter the mask and thus increase the opacity of masks to infectious viruses by up to a factor of 50. In addition, the majority of the virus particles released from the mask after use are non-infectious.
Ftema W. Aldbea Sebha University, Libya
Structural Properties of Iodine doped Zinc Oxide Nanoparticles at Different Synthesis Temperatures
Iodine-doped zinc oxide (Zn1-xOIx, x = 0.2) samples have been prepared by the sol-gel method. The samples were sintered at 300oC and 400 o C on air for 2hrs. The X-ray diffractometer (XRD) results showed the hexagonal wurtzite structure of the sample. The crystalline size of samples is affected by the sintering temperature. The field emission scanning electron microscope (FESEM) morphology of the sample sintered at 300o C and 400 o C exhibited a mixture of short rods and sheets. Raman analysis of samples at different sintering temperatures was also discussed.
Jae Soo Yoo Chung-Ang University, Korea
Wave energy-assisted fluidic self-assembly of micro-LED chips for display module fabrication
Micro-LED displays have excellent image characteristics, particularly in terms of contrast ratio, response to electric field, and color expressions. However, a lot of technological challenges remain unsolved. The rapid and accurate arrangement of a few million chips with a size of ∼ 50 µm to form pixels on the backplane is a critical one of challenging tasks. In this presentation, fluidic self-assembly process is demonstrated for LED module fabrication. With geometric constraints, wave energy is used as the external force to manipulate the LED chips on the substrate. Target-generated waveforms in the fluid control the magnitude of moving force as well as the direction of optical flow of micro-chips in our experimental apparatus, in which the micro-LED chips are arranged on a pattern-designed substrate, i.e. transfer cartridge, in computer-controlled way. Then, the array of micro-chips are transferred to a circuit-printed glass plate by face-to-face pressing under high temperature and high pressure. This kind of approach is demonstrated to be very creative and supportive to the very powerful manufacturing scheme with low cost of fabrication for various type of products to meet high-end consumer needs in display industries. For this purpose, 1” LED display module, which is fabricated in wave energy-assisted fluidic self-assembly, is demonstrated in this presentation.
Mengmeng (Dawn) Xu The University of Western Australia, Australia
Monoclinic angle mediated negative thermal expansion behaviour of NiTi
Near-equiatomic NiTi alloys exhibit a first order B2→B19' martensitic phase transformation.
The B19' phase has a monoclinic crystal structure with a monoclinic angle of 97.8°. This
monoclinic lattice distortion is the root cause of the shape change output and recovery of the
alloy going through this transformation. Recent studies by means of DFT calculation and
molecular dynamics simulation indicate that the monoclinic angle of the B19' phase is not a
fixed value but can change continuously in a second order transition nature under the influence
of stress or temperature. This study aims to utilize this second order change of the monoclinic
angle of the B19' phase to create a novel thermal expansion behaviour of these alloys, including
nil or negative linear coefficient of thermal expansion. This is achieved by cold working to
introduce internal stresses and to preset a monoclinic angle which is allowed to change
continuously upon subsequent heating and cooling, thus, to achieve the novel thermal
expansion behaviour. The phase structure and the evolution of the monoclinic angle of the
samples were analyzed by means of X-ray diffraction and the thermal dilation behaviour was
characterized by means of thermomechanical analysis. It was found that cold worked NiTi wire
alloys showed a negative linear thermal expansion behaviour along wiredrawing direction
within a temperature range of -150 °C ~ 80 °C. The monoclinic angle of the B19' phase in the
cold worked alloy wire was also measured to change within this temperature range. These
findings demonstrate a new approach to designing novel materials of unusual thermal
Hiroki Gonome Yamagata University, Japan
Electricity-free lighting system bioinspired by Haworthia obtusa
Electricity plays an important role in modern societies, with lighting and illumination accounting for around a fifth of global electricity demand. Haworthia obtusa has the remarkable ability to collect sunlight through a 'window', allowing it to photosynthesise in the dark. Inspired by this unique feature, we have developed a novel lighting system that uses no electricity. The 'window' of Haworthia obtusa is replicated using a scattering medium that collects solar light and directs it to an optical fibre. The optical fibre then carries the light inside where lighting is required. The effectiveness of this unique lighting system has been confirmed both numerically and experimentally. In the numerical evaluation, the Monte Carlo method was used to calculate the effect of the technique by analysing the radiative transfer in the scattering medium. In the experimental evaluation, we fabricated the lighting system by attaching a scattering medium to the edge of an optical fibre...
Liang-Xing Lu Space Environment Simulation Research Infrastructure, Harbin Institute of Technology, China
Integrated modelling and simulation of laser powder bed fusion
In-depth understanding of the layer-by-layer process is critical for the quality control of additive manufactured (AM) components. Besides the development of experimental techniques, computational modelling is another important way to study the AM mechanisms in detail. However, currently there is still lack of a modelling platform that integrates all the necessary physics involved in the AM process. We have developed a modelling framework that integrates a phase field method for microstructure evolution, a lattice Boltzmann method for melt pool dynamics, a modified ray-tracing method for laser-material interaction, and a minimum gravity energy algorithm for powder bed generation. The integrated model well captures most of important phenomenon commonly observed in laser powder bed fusion (LPBF) process, such as the solid - liquid phase transformation, the fluid dynamics of melt pool including key-hole phenomena, the generation of defects both by lack of fusion and key-hole bubble spill-over, the balling effect, and the surface roughness etc.. Using the developed model, we have simulated the single-track LPBF process of NiTi shape memory alloy. Our simulation shows good agreements with experimental observations, and proves that different from keyhole depth, melt pool size does not obey the scaling law with line energy density, the keyhole depth and the overlapping ratio of laser spot vs. keyhole opening together determine the laser absorptivity. Based on the simulation finding, we also develop a self-consistent analytical model to predict the keyhole depth and the absorptivity for given scanning parameters. The present work lays a solid foundation towards quantitative understanding of multi-layer AM process.
Jeong Ho Cho Korea Institute of Ceramics Engineering and Technology, Korea
Ferroelectric Properties and Domain Structure of Bi0.5Na0.5TiO3-SrTiO3 Based Ceramics
The crystal structure, domain patterns, and ferroelectric properties of Fe-modified BNT-ST [0.77(Bi0.5Na0.5)TiO3-0.23Sr(Ti1-xFex)O3] ceramics were fabricated by a conventional solid-state reaction. The ferroelectric properties, microstructure and domain morphology were investigated with field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM).
Core-shell structures were observed and the volume fractions of the core-domain and shell (relaxor-matrix) were found to be dependent on Fe-modification content. The crystal structures of the core-domain and the relaxor-matrix were rhombohedral with the space group R3c, and the tetragonal with the space group P4bm, respectively.
Seokhun Jang Haven Co., Ltd., South Korea
The effect of shell additives on Bi0.5(Na0.78K0.22)0.5TiO3 based piezo-electric ceramics
BNKT Ceramics, one of the representative Pb free based piezo-electric ceramics, constitutes a perovskite (ABO3) structure. Since Bi, Na, and K sources constituting the A site are highly volatile at a sintering temperature of 1100 ℃ or higher, it is difficult to maintain uniformity of the composition. In order to solve this problem, there should be suppression of volatilization of the A site material or additional compensation of the volatilized. In this study, the basic composition of BNKT Ceramics was set to Bi0.5(Na0.78K0.22)0.5TiO3 (= BNKT), and volatile site (Bi, Na, and K sources) were coated in the form of a shell to compensate additionally for the A site ions. In addition, the physical and electrical properties of BNKT and its coated with shell additives (= @BNK) were compared and analyzed, respectively. As a result of analyzing the crystal structure through XRD, both BNKT and @BNK had perovskite phases, and the crystallinity was almost similar. The average particle size(D50) of BNKT and @BNK was 1.67 um and 5.47 um, and the sintering density was 5.86 g/cm3 and 5.65 g/cm3, respectively. The Curie temperatures of the two sintered bodies were almost the same(TC = 290 to 300 ℃), but the values of d*33 and Pr were different. (d*33; BNKT= 365.09 pm/V, and @BNK= 280.92pm/V, Pr; BNKT= 33.8.uC/cm2, and @BNK=27.08 uC/cm2) The experimental results indicated that the additional compensation for a shell additive causes the coarsening, resulting in a decrease in sintering density. However, coating shell additives to compensate for A site ions is an effective way to suppress volatilization.
Ángel Ríos University of Castilla – La Mancha, Spain
Achievements of Capillary Electrophoresis in Analytical Nanometrology
Nanoscience and Nanotechnology (N&N) have had a deep impact in Analytical Chemistry . On the one hand, analytical chemists welcome the challenge and opportunities that N&N offer in this area because of both the powerful nanotools to improve analytical properties of results of analytical processes and analysis of the nanoworld. On the other hand, the basic (Nanoscience) and applied (Nanotechnology) developments and achievements need information from the nanoworld to fulfil their respective objectives and to make founded and timely decisions. Just in this last way, the determination of nanomaterials (nanoparticles in many cases), in specific types of samples is a recognized challenge in today analytical science.
Analytical Nanometrology (ANM) merges as the metrology applied to nanomaterials for analytical purposes. It has two different facets, not mutually exclusive : the characterization of nanomaterials (NMs) by themselves, and the determination of NMs in particular types of samples..
Silvia Rincón Pérez Industrial University of Santander, Colombia
Formulation of bituminous emulsions from binder materials with the presence of inorganic solids.
This research aimed to characterize and evaluate the performance development of bituminous binder material (MBL) with the presence of inorganic solids from petroleum production and refining residues, as an oily phase in the formulation of stable emulsions. A large amount of oily waste is produced yearly, bringing soil and water contamination in the rural population. For this reason, it is necessary to find new alternatives for the treatment of oily waste that mitigate the environmental and social impact of waste. First, physicochemical characterization studies were performed to analyze the types of hydrocarbons, viscosity, moisture content, density, cementing products, asphaltenes content and X-ray diffraction of two bituminous materials, with mineral filler content between 10-25% . Cationic surfactants are traditionally used for the formulation of emulsion applied in soil stabilization and surface treatments; however, in this study, anionic and cationic emulsifiers have been used with in the formulation of bituminous emulsions from previously mentioned binder material..
Wein-Duo Yang National Kaohsiung University of Science and Technology, Taiwan
Study on hydrothermal technology for preparation of the heteroatom doped Mn3O4-carbon electrode for supercapacitor
In this study, chitosan (C) was used as the source of carbon for skeleton, carbon fiber cloth
(CC) was used as the electrode substrate, and the flower-like nanostructure Mn3O4@C/CC
nano-electrode material as the positive electrode of supercapacitor prepared by hydrothermal
method. Using SEM, TEM, XPS, XRD, and BET analyses, the microstructure and properties
of the as-prepared Mn3O4@C/CC material was characterized and investigated. Cyclic
voltammetry (CV), galvanostatic charge-discharge test (GCD) and cycle performance tests
were performed in 1 M Na2SO4 electrolyte to reveal its electrochemical behavior. Due to the
addition of carbon material, the specific surface area of the material is greatly increased, and
the specific capacitance of the material is increased. The specific capacitance of the as-obtained
Mn3O4@C/CC electrode reaches 195.2 F g-1 at 1 A g-1. In addition, phosphoric acid (H3PO4)
was further added as a phosphorus (P) source, and carbonized chitosan was co-doped on the
framework of nitrogen source to synthesize Mn3O4@NPC/CC electrode. Under the charge and
discharge current of 1 A g-1, the capacitance has been greatly improved to 256.8 F g-1. The use
of chitosan as carbon skeleton can improve the electrochemical properties of the electrode, and
it has the advantages of low cost, environmental protection and sustainable development, the
most promising research on supercapacitors.
Sanjeev Das National Institute of Technology Raipur, India
Development of Force Convection Casting Technologies for producing high-quality Aluminium-based products
The major consumers of wrought aluminum (Al) products are the aerospace and automotive industries where weight reduction is the primary goal. The strength of metals and alloys can be further enhanced by reducing its average grain size. Also, transforming the cast columnar grain structure into an equiaxed grain structure improves the formability and reduces the macro-segregation of the cast product. Presently various grain refiners (GR) are used by the industries to obtain fine equiaxed grain structure. For achieving effective grain refinement, specific addition process GRs have to be followed. Or else, challenges like GR segregation and fading may occur, which may lead to the production of a poor-quality product. Force convection (FC) technology is one of the technologies, which shows significant refinement in grain size in cast alloy without the addition of GRs. FC can be created by the external fields, i.e., Mechanical stirring, Electromagnetic field, and Ultrasonic cavitations process..
Sayyeda Marziya Hasan Shape Memory Medical Inc., USA
Tuning Thermo-Mechanical Properties of Shape Memory Polymer Foams for Biomedical Applications
Shape memory polymers (SMP) are smart materials that undergo shape change upon input of an external stimulus such as heat, electricity, or pH change.1 SMPs can be programmed into a secondary shape, but recover to their original shape when a stimulus is applied.1,2 Our group has utilized these smart materials to develop self-actuating foam plugs that are used for vascular occlusion.3 The IMPEDE Embolization System consists of a series of SMP foam plugs that passively actuate in vivo to cause vessel occlusion. Vascular occlusion is the primary way to treat aneurysms, endoleaks, and other vascular abnormalities.3 Transition temperature of the self-actuating polymer is an important feature to understand and control to adjust the expansion profile of the material for a desired application. This presentation will focus on the modification of thermo-mechanical properties of amorphous polyurethane SMP foams to control their actuation profiles so that they are suitable for a vascular occlusion device.
Prof. Vistasp M. Karbhari University of Texas Arlington, United States
Thermomechanical Characterization of Effects of Thermal Aging of Carbon/Epoxy Composites
Carbon/epoxy composites fabricated using non-autoclave cure processes using ambient or low-moderate temperature cure are increasingly used in civil, naval and offshore applications that require good long-term durability under harsh environmental conditions including exposure to heat and elevated temperatures. This research reports on the effects of thermal aging on these composites over a range of elevated temperatures (66-232 oC) for periods upto 72 hours using DSC, DMTA and TGA based characterization. It is shown that thermal aging results in a competition between post-cure and progression of cure resulting in an increase of Tg and thermos-mechanical characteristics and thermal deterioration including matrix cracking and fiber-matrix debonding as well as interphasial degradation. Effects are compared based on three techniques to emphasize the need for multiple characterization methods to ensure that true trends and progression is identified which can then be used for the development of a comprehensive understanding of durability of these materials.
Armando Genco Politecnico di Milano, Italy
K-space hyperspectral imaging of photonic devices and metasurfaces
Fourier-plane optical microscopy is a powerful technique for studying the angularly-resolved optical properties of a plethora of materials and devices. The information about the direction of the emission of light by a sample is extracted by imaging the objective back focal plane on a two-dimensional detector, via a suitable optical system. This imaging technique allows to provide angle resolution over a wide angular field of view, but typically it doesn’t provide any spectral information since it integrates the light intensity over a broad wavelength range.
In this work, we combine the concept of hyperspectral imaging with Fourier-space microscopy, and we apply the technique to the characterization of planar organic microcavities and dielectric metasurfaces. We perform hyperspectral imaging by high-throughput Fourier-transform spectroscopy: we employ a common-path birefringent interferometer to generate the two delayed replicas, whose interference pattern is measured as a function of their delay. The Fourier Transform of the resulting interferogram yields the intensity spectrum as a function of the wavelength for each point of the microscope angular field-of-view. This approach provides in just one measurement an angle-resolved hyperspectral view of the samples with an angular resolution of 0.3°, and a spectral resolution of less than 0.1 nm in terms of peak shift, and 4 nm in terms of peak broadening. The hyperspectral Fourier-space imaging clearly showed the parabolic angular dependence of the resonance modes of a microcavity in photoluminescence. From the hyperspectral image, we reconstruct a 3D image of the paraboloid, fully characterizing the cavity dispersion across the whole Fourier space. Furthermore, we apply our technique for the investigation of a dielectric nanostructured metasurface consisting of an array of GaP nanodisks, revealing an anapole mode with unusual polarization-dependent angular and spectral behaviour, confirmed by our finite differences time domain simulations.
Elida de Obaldia Universidad Tecnológica de Panamá, Panama
Study of Atomic Hydrogen Concentration in Grain Boundaries of Polycrystalline Diamond Thin Films for energy storage applications
Polycrystalline diamond films were grown, using hot filament chemical vapor deposition (HFCVD), which resulted in structures ranging from Ultrananocrystallyne Diamond (UNCD) with grain sizes of 2 - 5 nm diameter, to nanocrystalline diamond (NCD) with 10-500 nm grains, to microcrystalline diamond (MCD) with grain sizes in the range 0.5-3 mm in diameter, depending on the growth conditions (CH4 gas flow constant at 2 sccm, while changing the H2:Ar flow ratios (10:90, 25:75, 50:50, 75:25 sccm in the gas mixtures, to grow UNCD to NCD films, and H2 (200 sccm)/CH4 (3 sccm) to grow MCD films, filament to substrate distance (20 mm), substrate temperature (550-725 ˚C), and time (2, 4, 8 hrs)). Research revealed that the structure and properties of the polycrystalline diamond films, mentioned above, are correlat4ed mainly with the density and chemical bonds in grain boundaries. Studies included detailed analysis of films’ morphology, chemical, crystallographic and electrical properties of the PCD films, revealing that the grain boundaries (5 nm to 1 mm width) play a critical role in films’ properties. Measurements revealed a linear correlation between the H atoms concentration in the PCD films and the grain size. The experimental data can be explained by a simple model related to the grain boundaries, where the density of dangling C atoms bonds correlates with the concentration of Hydrogen atoms in the films. The simple model assumes crystalline grain structures involving sp3 diamond-type C bonds with 2 dangling bonds passivated with a hydrogen atom. Raman results are also explained with this model considering that the trasnpolyacetelyne signal correlates with C=C and C-H bonding at the grain boundaries. Conductive atomic force microscopy (CAFM) measurements showed that electrical conduction through PCD films is mainly controlled by grain boundaries, most probably due to electron insertion into them via H atom bonding to dangling bonds of C atoms, resulting in the release of electrons. UPS measurements showed that the work function for the electrons in the PCD films is independent of grain size, reinforcing the idea that the makeup of the grain boundaries is the same for all PCD films.
Andrew Vaillant Replicor Inc., Canada
Nucleic acid polymers: a new take on an old polymer chemistry
For more than 30 years, oligonucleotide-based drugs have focused on their sequence-dependent hybridization with mRNA inside the cell to interfere with gene function. However, oligonucleotide polymers also contain distinct chemical activities mimicking those found in other bioactive polymers. Unlike these earlier bioactive polymers, nucleic acid polymers (NAPs) can be tuned by chemical modification to adopt a strong amphipathic character in the presence of uncomplexed amphipathic alpha helices in proteins. This induction drives a novel, high affinity interaction between NAPs and a diverse but structurally related family of proteins involved in a broad spectrum of viral infections. Unlike earlier polymers, NAPs naturally accumulate in the liver and are very safe and well tolerated, making them ideal antiviral agents for infections of the liver.
Chronic hepatitis B (HBV) and hepatitis delta (HDV) liver infections affect 300 million people worldwide with 820,000 deaths annually due to liver failure and liver cancer. The lead NAP candidate, REP 2139 is the result of several additional NAP optimizations driven by clinical experience of earlier NAPs in these infections. REP 2139 has now been evaluated in phase II trials in HBV and HBV / HDV infection and is achieving high rates of cure of both these infections, outcomes which are not possible with currently approved medications. REP 2139 is now currently being deployed in a compassionate access program worldwide in infected patients with very advanced liver disease with success in rescuing these patients from liver failure.
Jie Luo Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, China
VO2 Nanosheets Supported on Carbonized Cotton Fabric as Bifunctional Textiles for Flexible Pressure Sensors and Zinc-Ion Batteries
Flexible pressure sensors and aqueous batteries devices, as promising wearable electronics, have been received a great deal of attentions. The synergistic functionalities of versatile electrode materials with multidimensional architectures are recognized to have a significant impact on the performance of flexible electronics. In this work, a facile hydrothermal strategy was designed to conformally grow vanadium dioxide nanosheets on carbonized cotton fabrics (VO2/CCotton), which is a candidate material used in flexible piezoresistive sensors. As a result, the VO2/CCotton based pressure sensor demonstrated high sensitivity (S = 7.12 kPa−1, 0−2.0 kPa) and a stable sensing ability in a wide pressure scale of 0−120 kPa. Further practical applications were performed in monitoring a series of physiological signals as well, such as twisting, blowing, and voice vibration recognitions etc. In addition, investigation of energy storage application was also performed due to the excellent electrochemical properties. A flexible quasi-solid-state aqueous zinc-ion battery (FAZIB) was sandwich-structure assembled with VO2/CCotton as the cathode, gel electrolyte and Zn nanosheets/carbon nanotube film as the anode. The FAZIB device obtained a capacity as high as 301.5 mAh g−1, and presented remarkable durability of 88.7% capacity retention after 5000 cycles at 10 A g−1. These exceptional outcomes are attributed to the unique three-dimensional architecture and the prominent synergetic effects of CCotton and VO2 and allow for the proposal of novel guidelines for next-generation intelligent flexible wearable electronics.
Bruno Martins de Souza Military Institute of Engineering, Brazil
Electrodeposition of graphene oxide on dental implants: an alternative for surface treatment
The application of graphene-based materials has been investigated in tissue engineering. This material can be incorporated to the surface of implants in a row to reduce the formation of bacterial biofilm and improve adhesion of osteogenic cells. The objective of this work was to evaluate the feasibility of deposition of graphene oxide on the surface of purchased implants and correlate the benefits in biological properties. For this study, 4 implants machined with external hexagonal connection, 4 implants with surface treatment treated with acid with external hexagonal connection, 4 Ticp discs grade 4 without surface treatment and 4 Ticp discs grade 4 with surface treated with acid. The samples were provided by the company Conexão Systems. The specimens were admitted to the graphene oxide electrodeposition treatment. After treatment, the bodies were analyzed using a scanning electron microscope to identify graphene oxide deposition and with a goniometer to assess the effect of this technique on implant mobility. The results obtained showed that the electrodeposition of graphene oxide on the surface of the implants covered a wide area of adhesion and positively affected their mobility. It can be concluded that the surface treatment technique with graphene showed a promising alternative to prevent peri-implantitis and improve the surgery involved in osseointegration.
Fetiye Esin Yakin Sabanci University, Turkey
An experimental investigation of static and dynamic mechanical properties of different ply orientations of carbon fiber reinforced composites under elevated service temperatures
The varieties of the design of ply orientations give excellent properties to carbon fiber reinforced polymer composites (CFRPCs) for utilization in the advanced engineering industries for instance; their advanced chemical resistance, high strength-to-weight ratio, and well-established supply chain. However, the elevated service temperature of aerospace applications causes significant drawbacks not only to the microstructural but also mechanical properties of the CFRPCs. Therefore, the aim of our study is to identify the effect of static and dynamic mechanical properties of the uni-directional (UD- [0°]) and cross-ply (CP- [0/90/0°]S) ply orientations of the CFRPs by short beam shear (SBS) tests and dynamic mechanical analyses (DMA) when the elevated temperatures test environment were predominant during static and dynamic mechanical tests. According to the results, SBS test results showed that UD composites outperformed CP composites by 14.5%, 39%, and 54% at room temperature (RT), 110°C, and 170°C test temperature conditions, respectively. To understand the effect of elevated temperatures on damage evolutions and variations of different fiber orientations, SBS test specimens were elaborately examined with optical microscopy analysis. The optical microscopy results promoted the void content variations and the failure mechanisms due to the variation of the ply orientations of CFRPs. On the other hand, at RT, the UD composite had a storage modulus of 12.6% higher than the CP composite, while at 110°C and 170°C, the modulus of CP composites was 9.8% and 22.5%
higher, respectively. The current investigations in our study are outstanding for comprehension of the effect of the physic of fiber orientation on mechanical strength values as a function of temperature.
Rolf Sandström KTH Royal Institute of Technology, Sweden
Basic modelling of strength properties
Physical properties can in many cases be accurately predicted with ab initio or thermo¬dynamic models. On the other hand, for dislocation controlled properties such as strength and ductility it has been necessary to resort to empirical expression with a number of adjustable parameters to describe experimental data. However, in recent years, basic models for mechanical properties based on physical principles have been developed. For example, such models have been proposed for time dependent creep properties including creep rate, rupture and ductility without involving any adjustable parameters1,2,3. It has been demonstrated that the models can cover a wide range of conditions in temperature and stress. In fact, this means that the models can be extrapolated by many order of magnitude in the creep rate which is not possible with empirical approaches4.
Although empirical models are simple to use and can easily be applied to represent experimental data, they have a number of drawbacks. They cannot be used to predict and extrapolate values outside the range of the data set unless a large set of data is available. In addition, the empirical models cannot be applied to identify the operating mechanism since a number of such models can fit the same data in general. With the appearance of the basic models, these difficulties have been removed. In the presentation a survey of basic models will be given.
Tania Guadalupe Peñaflor Galindo National Institute of Technology, Nagaoka College, Japan
Study of the interfacial effect of the hydration layer on fibrinogen adsorption and fibroblast adhesion states on nanoparticulated hydroxyapatite films
In a biological environment, the adequate cell response to biomaterials such as hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is determined by the interactions with the adsorbed proteins which are strongly influenced by the water at the interface (hydration layer), this hydration layer has a significant role on determining the structure, dynamics, and bioactivity of the proteins. A comparative study of the hydration layers on elliptical-shape-HAp (E-HAp), needle-like-shape-HAp (N-HAp), and Au films was achieved to investigate the interfacial effect of the hydration layers on the conformation of the adsorbed fibrinogen (Fgn) and fibroblast adhesion properties. The ratios of three types of hydration layer states (free water, intermediate water, nonfreezing water) were analyzed by a Fourier Transform Infrared (FT-IR) spectral deconvolution of the O−H stretching absorption band. The ratio of the bonding water state (i.e., intermediate and nonfreezing water molecules) was almost the same between the two HAp films, and the E-HAp film exhibited the smallest ratio of nonfreezing water, which can suppress the denaturation of the adsorbed protein. Subsequently, FT-IR spectral deconvolution results of the amide I band of the adsorbed Fgn on the E-HAp film had a higher proportion of α-helix and β-sheet structures as compared with N-HAp and Au films, suggesting that a smaller proportion of nonfreezing-water would play a significant role in the stereoscopic Fgn conformation. In fibroblast culture, the FT-IR spectra of the adhered cells on HAp, N-HAp, and Au films exhibited different absorbance intensities of the amide A, I, II, and III bands, suggesting a different number of collagen-producing states by the cells, which were also supported by immunostaining results of the collagen type I. Therefore, the different hydration structures on the films clearly influenced the conformation of the adsorbed protein, and the preferential conformation was found at the interfaces between the fibroblasts and the underground E-HAp films.
Moran Aviv Tel Aviv University, Israel
Effect of fluorine atom position in Fmoc-Phe derivatives on its physical and antimicrobial properties
Supramolecular hydrogels formed by the self-assembly of amino-acid based gelators are receiving increasing attention from the fields of biomedicine and material science. Self-assembled systems exhibit well-ordered functional architectures and unique physicochemical properties. However, the control over the kinetics and mechanical properties of the end-products remains puzzling. A minimal alteration of the chemical environment could cause a significant impact. In this context, we report the effects of modifying the position of a single atom on the properties and kinetics of the self-assembly process. A combination of experimental and computational methods, used to investigate double-fluorinated Fmoc-Phe derivatives, Fmoc-3,4F-Phe and Fmoc-3,5F-Phe, reveal the unique effects of modifying the position of a single fluorine on the self-assembly process, and the physical properties of the product. The presence of significant physical and morphological differences between the two derivatives was verified by molecular-dynamics simulations. Analysis of the spontaneous phase-transition of both building blocks, as well as crystal X-ray diffraction to determine the molecular structure of Fmoc-3,4F-Phe, are in good agreement with known changes in the Phe fluorination pattern and highlight the effect of a single atom position on the self-assembly process. Interestingly, these derivatives show different antibacterial properties against various gram-positive and gram-negative bacteria. These findings prove that fluorination is an effective strategy to influence supramolecular organization on the nanoscale. Moreover, we believe that a deep understanding of the self-assembly process may provide fundamental insights that will facilitate the development of optimal amino-acid-based low-molecular-weight-hydrogelators for a wide range of applications.
Bekir Dizman Sabanci University, Turkey
Polyoxazoline-Imidazole Based Thermal Latent Curing Agents for One- Component Epoxy Resins
Polymer matrix composites (PMCs) are the most widely used composites due to their ease of
preparation, lightweight, and durability. Epoxy resins are the most commonly utilized polymer
matrices for the manufacturing of PMCs due to their superior properties. They are utilized in
PMCs as either two-component epoxy resins or one-component epoxy resins (OCERs). OCERs
are ready-to-use systems that are designed to overcome the drawbacks of two-component
epoxy resins such as short shelf-life, low energy efficiency, uncontrolled curing temperatures,
and risk of human error. OCERs are comprised of epoxy resins and latent curing agents.
Thermal latent curing agents (TLCs) are the most commonly used latent curing agents in
OCERs. In this work, polyoxazolines (POZs) with finely tunable properties were prepared and
used along with imidazole (Im) curing agent to obtain TLCs. POZ-based TLCs either in the
form of POZ-Im complexes or POZ-Im conjugates were prepared and used with diglycidyl
ether bisphenol A (DGEBA) epoxy resin to prepare OCERs. POZs were characterized by 1H
NMR, FTIR, GPC, TGA, and DSC. POZ-based TLCs were characterized by FTIR and optical
microscopy. Cure kinetics studies were carried out by dynamic and isothermal DSC to
investigate the curing behavior of the prepared OCERs. The effect of parameters such as Im
content, POZ:Im ratio, POZ molar mass, and the type and number of pendant groups on thermal
latency behavior was investigated. The results demonstrated that the developed OCERs
provided latency in curing and had longer shelf-lives compared to OCERs created with Im.
Yasuhiko Orita School of Materials and Chemical Technology, Tokyo Institute of Technology, Japan
Formation mechanism of surface modified nanocrystals using controlled hydrolysis reaction in high-pressure CO2
Surface-modified metal oxide nanocrystals (NCs) have attracted considerable interest because surface modification significantly reduces the surface energy and improves their dispersity in the solvent, which has promoted the development of its direct-synthesis methods such as heat-up1 and hydrothermal methods2. However, these methods typically cause the large amount of the liquid waste for the synthesis and washing of NCs, where the disposal and the regeneration cost of them are known as critical issues. Whereas supercritical carbon dioxide (scCO2) can be appealing reaction field to synthesize surface modified NCs. ScCO2 has high solubility of metal organic precursor and high diffusivity, which allows the formation of homogenous phase, while the synthesis in scCO2 is substantially solventless process. Thus, scCO2 medium has been applied for the synthesis of inorganic materials such as metal oxide, metal hydroxide and metal sulfate. However, in the most of case, the products were observed as aggregates or the submicron sized particles after the synthesis in scCO2. This is probably due to the non-polar properties of scCO2 that have low compatibility with metal oxide surface (generally is hydrophilic), which typically results in the accelerated aggregation. However, the introduction of organic surfactant to the synthesis in scCO2 is expected to overcome this problem because surface modification can change surface property of metal oxide from hydrophilic to hydrophobic that is compatible to scCO2. Additionally, the surface modification could induce strong steric repulsion force between NCs. These expectations led to the direct synthesis research of surface modified NCs, which are reported by the authors3, 4.
In this contribution, we introduce the novel synthesis of surface modified iron oxide NCs in scCO2 with various amounts of water and the formation mechanism with the hydrolysis reaction to control the size, surface property and aggregation state of NCs.
Anthony P. Marino Texas A&M University, College Station, United States
Effects of print parameters and heat treatment on fatigue of laser powder bed fused Inconel 718
Laser Powder Bed Fusion (L-PBF) allows for complex geometry parts to be fabricated without sacrificing mechanical properties/behaviors. Though this process is greatly beneficial, it is still hindered by its build volume capabilities as well as the present of detrimental particles and defects in its microstructure after the printing process. This research applies to the printing parameters and post processing of L-PBF’ed Inconel 718 (IN718) and their effect on fatigue performance of the material. Samples were printed with laser speed varying from 1000-1500 mm/s while varying energy density per volume from 45.5-68.2 J/mm3. Samples were grouped and subject to different heat treatment (HT) combinations including homogenization (HG), hot isostatic pressing (HIP), and solution aging (SA). The porosity and microstructures of the samples were analyzed through optical and scanning electron microscopes (OM and SEM, respectively) to determine optimal print parameter and heat treatment strategy. The lowest amount of porosity with the smallest average pore diameter (15.58μm) was observed in samples printed with 54.5 J/mm3 energy density.
Francisco López-Serrano National Autonomous University of Mexico, Mexico
A Simple Model for Pickering Emulsion Polymerization: Styrene in a Semicontinuous Process as a Case Example
The potential for emulsifier-free hybrid-nanoparticles in diverse applications such as drug delivery, enzyme fixation, catalysis, photo-catalysis, coatings, among others, strongly motivates their study and understanding—both in academia and industry. Ramsden (1903) and Pickering (1907) first described the finding that solid particles could be used to stabilize droplets—this was termed Pickering-type stabilization. A “Pickering emulsion polymerization” is an emulsion polymerization process in which the colloidal stability is mainly imparted by tiny solid particles adsorbed at the interface of polymer latex particles (Bon, 2015). Pickering particles also modify the polymerization rate, kinetics, and other factors such as pH and monomer/water/initiator/Pickering-agent ratios. These have a sizeable effect on polymerization rate, particle size, coverage ratio, particle morphology, and average number of radicals, and all are interconnected. In this work, data from the literature (Brunier et al., 2015) regarding the semicontinuous Pickering emulsion polymerization of styrene at 70 ºC, at different Laponite levels, are used to develop a simple model describing monomer conversion (x), average number of radicals (ñ), particle density (Np; L-1), and reactor volume (V; L) evolution. The monomer concentration inside particles (Mp) did not show a constant value, as expected in a semicontinuous process.
Damaris Chieregato Vicentin Federal University of Sao Carlos, Brazil
Materials Science and Engineering
Analyze of Finite Mixture and EWMA Control Charts for Multiple Stream Monitoring
Erico Souza Teixeira CESAR School, Brazil
An artificial neural network model to predict structure-based protein– protein free energy of binding from Rosetta-calculated properties
The prediction of the free energy (ΔG) of binding for protein–protein complexes is of general
scientific interest as it has a variety of applications in the fields of molecular and chemical
biology, materials science, and biotechnology. Despite its centrality in understanding protein
association phenomena and protein engineering, the ΔG of binding is a daunting quantity to
obtain theoretically. In this work, we devise a novel Artificial Neural Network (ANN) model
to predict the ΔG of binding for a given three-dimensional structure of a protein–protein
complex with Rosetta-calculated properties. Our model was tested using two data sets, and it
presented a root-mean-square error ranging from 1.67 kcal mol-1 to 2.45 kcal mol-1, showing
a better performance compared to the available state-of-the-art tools. Validation of the model
for a variety of protein–protein complexes is showcased.
Wei Chen The University of Texas at Arlington, United States
The Invention of Copper Cysteamine for Photodynamic Therapy – Deeper and Better
Here we introduce a new material called Copper Cysteamine we invented for applications in cancer and infection treatment as well as applications in lighting, sensing and water purification. Photodynamic therapy is a combination of light and sensitizers for cancer treatment. The sensitizers and the light are non-toxic but when they interact each other toxins like reactive oxygen species are generated that can kill cancer cells. Photodynamic therapy has the beauty of targeting tumors by the sensitizers themselves and the light, so its side-effect is much lower than chemotherapy or radiotherapy. However, the need of light for activation has some limitations as light cannot penetrate deeply into tissue, so photodynamic therapy has been widely used for skin disease treatment but not for deep cancer treatment. In this webinar, I will discuss the possible solutions for developing photodynamic therapy for deep cancer treatment and some new progress in Photodynamic therapy and the invention of new sensitizers that can be activated by UV, X-ray, microwave and ultrasound to produce reactive oxygen species for deep cancer treatment as well as immunity enhancement. New ideas for the combination of photodynamic therapy and radiation to overcome radiation resistance will be discussed. In addition, the potential applications of this kind of new materials in other areas like water treatment, lighting, sensing and plant growth will be briefly introduced.
Willfried Kunz Hochschule Karlsruhe - University of Applied Sciences, Germany
Establishing a data-driven structure-wicking relationship for porous membranes
The demand for rapid and user-friendly medical diagnostic devices, known as Point-of-Care-Testing (POCT), has surged in recent years. Among these devices, lateral flow assays (LFAs) have gained popularity due to their cost-effectiveness and ease of use. LFAs rely on capillary-driven liquid transport through highly porous and open-pored membranes, commonly known as wicking, to a reaction zone. However, the underlying interaction mechanisms and microstructural characteristics of these membranes are not fully understood, even for widely used COVID-19 rapid tests.
To address this gap in knowledge, we use a data-driven approach that establishes the linkages between the structure of highly porous open-pored polymeric membranes, and the capillary-driven fluid transport through them. Using fluid flow simulations and image analysis methods, we algorithmically generate and characterize about 300 porous microstructures with varying geometrical features in 3D. By analyzing this data, we can make predictions about the propagation time of a fluid over definable distances, based only on the microstructural properties of porosity and ligament radius.
Sadykov Dinislam ITMO University, Russia
Peculiarities of manifestation of AIH and DIS in UFG CP Al structured by various SPD methods
Al conductors are used to create high-voltage power lines and power transformers windings to ensure the functioning of various industrial facilities. The key disadvantage limiting their use is their relatively low strength. In [1, 2], it was shown that the formation of an ultrafine-grained structure (UFG) in commercial pure (CP) Al by severe plastic deformation (SPD) methods and subsequent additional annealing leads to annealing-induced hardening (AIH), which provide excellent strength but low plasticity. In [1-3], it was shown that additional small deformation by SPD of an annealed UFG structure leads to deformation-induced softening (DIS), which provides good plasticity. The combination of these effects can provide high strength and acceptable plasticity for aluminum conductors. To apply these approaches in industry, it is necessary to understand the main microstructure parameters and physical mechanisms responsible for their manifestation.
In this work, we studied the influence of the parameters of the initial UFG structure in CP Al formed by the following SPD-methods: high pressure torsion (HPT), equal channel angular pressing (ECAP) and combination of ECAP and cold rolling (CR) on the AIH and DIS effects. It is shown, that both effects exist in all studied UFG structures, in HPT-structure these effects are large, in ECAP- and ECAP+CR-structure both effects are less pronounced. The analysis of the microstructure, showed that the key role in the AIH and DIS effects is played by the distribution of dislocations in the grain/grain boundary structure, which differs depending on the method of SPD structuring. In addition, outstanding combination of high strength (~210 MPa), high electrical conductivity (~62 %IACS) with functional plasticity (8-10%) and thermal stability (up to 150 oC) was achieved for UFG CP Al, structured by ECAP+CR and annealed at 150 оС, 1h, for the first time.
Robert Honkanen Renaissance School of Medicine/Stony Brook University, United States
Novel advances in ocular impression cytology: Applications to translational studies and drug discovery
Impression cytology (IC) is an important, perhaps underutilized, technique for collection of cells from the superficial layers of the ocular surface. Although simpler compared to other cell acquisition methods, its major limitations remain the lengthy and often very elaborate sample processing. To overcome these limitations, we developed two important advances improving IC practicality, and greatly expanding its utility for studies of ocular disease pathophysiology and novel drug discovery.
Innovation #1: Using a novel triblock copolymer of collagen type I, polyethylenimine and poly-L-lysine, cells collected on a mixed cellulose ester membrane are firmly crosslinked / attached to a glass slide by heating and cooling. The membrane is removed after softening in an alcohol solution. This process reduces the time for transfer and preparation of cells from over 1 day to just 10–15 minutes, and also produces a nearly quantitative yield of transferred cells from the membrane to the glass slide (superior to previous methods).1
Innovation #2: A simplified process allows for ex-vivo culture of conjunctival cells harvested using IC onto a mixed cellulose ester membrane. Cultured cells remain 100% viable at 24 h, and 43% viable at 72 h and maintain their biological integrity, shown by cytokine and gene expression profiles. Cultured cells can be transfected with informative plasmids for use in mechanistic studies.2 These cells can be used to study effects of candidate drugs allowing evaluation in human samples prior to regulatory approvals, expediting drug development. Following ex vivo studies, cultured IC cells may be transferred to glass slides for analysis using Innovation #1.
Polya M. Miladinova University of Chemical Technology and Metallurgy, Bulgaria
Synthesis, dyeing ability and photostability of new reactive triazine dyes
New orange and red reactive dyes, derivatives of I and H acid, two of them bisdichlorotriazine and two bismonochlorotriazine, containing a stabilizer residue in their molecule (Figure 1) have been synthesized.
Figure 1. Structure of the synthesized dyes
They were evaluated for applicability on cotton. The degree of exhaustion, fixation and the fastness properties of dyed cotton samples of washing, acidic and alkaline perspiration, dry and wet rubbing were assessed. The optical properties as colour coordinates – L*, a*, b*, C* and h* from the CIE Lab colour space were examined of the resulting textile samples. The photostability of the dyes in water solution was studied spectrophotometrically and the photostability of the cotton samples dyed with the synthesized dyes have been determined by a change of colour coordinates. As a result of the studies carried out it was found that with the reactive dyes with the same chromophore without regard to type of the substituent in triazine ring, samples with similar colour shades, uniform colouring and stable colour were obtained. It was found that the introduction of 4-amino-2,2,6,6-tetramethylpiperidine fragment in the dye molecule increases the photostability in solution with 20-25 %. The degrees of exhaustion and fixation were bigger for the dyes containing bisdichlorotriazine residue, but the change in the colour characteristics of the dyed with containing a stabilizer residue dyes was weaker.
Dimka Ivanova Fachikova University of Chemical Tehnology and Metallurgy, Bulgaria
A comparative study of calcium phosphate coatings for biomedical applications
The calcium phosphate coatings on metallic implants are widely used for biomedical applications. The requirements for them are mechanical strength, good adhesion to the metal and high resistance in the human body. This work presents the results obtained during phosphating of high-alloyed steel simples in calcium-containing phosphates. The influence of composition and concentration of the components on the density, pH, conductivity, total and free acidity of the phosphating preparations are determined, as well as the effect of concentration and temperature of the working solutions on kinetics of obtaining coatings was also determined. The surface morphology of the coatings was investigated using Scanning electron microscopy (SEM). The chemical state and the atomic composition were determined by Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectrometer (XPS), respectively. The behavior and stability of phosphate coatings on high-alloyed steel in various physiological solutions, close to these in human body, was also investigated.
Sim Wan Annie Bligh Caritas Institute of Higher Education, Hong Kong
Key issues of multifluid side-by-side electrospun tri-layer Janus fiber
Based on our previous studies on side-by-side electrospinning and two-layer Janus nanofibers, tri-axial electrospinning and modified tri-axial electrospinning, here for the first time, we have developed a brand-new 3-fluid side-by-side electrospinning process, in which 3-layer Janus nanofibers are prepared. These 3-layer Janus nanofibers will then be exploited as a platform to design functional nanomaterials for potential application in wound dressings. In this presentation, the formation process of structure fiber will be addressed, which can provide a robust platform for various drug delivery systems.
Anna Łapińska Warsaw University of Technology, Poland
Carbon filler influence on thermal, EMI shielding, and electrical properties of polymer-based nanocomposites
In an era of advanced electronics, issues like adequate electromagnetic interference protection and effective heat dissipation are crucial due to the malfunctioning that they may cause. The high density of electronic elements forced by the miniaturization trend intensifies problems, and a solution is urgently needed.
Polymer nanocomposites are materials able to combine multiple features in one and may be treated as alternatives to currently existing solutions in providing electromagnetic compatibility (EMC) or effective heat dissipation. Therefore, comprehensive studies of electrical, thermal and electromagnetic shielding properties induced by graphene nanoplatelets and multiwalled carbon nanotubes are shown here..
Vladimir Kolkovsky Fraunhofer IPMS, Germany
Defects in oxides and semiconductors in modern microelectronics
The control over electrically active defects in oxides and semiconductors plays an important role in modern semiconductor industry. Such defects can be easily introduced during the growth of semiconductors or after various processing steps used for the fabrication of semiconductor devices. Even low concentrations of such defects may lead to significant modification or even degradation of the electrical characteristics of the devices. The detection and identification of defects is not a trivial task even in elemental semiconductors such as silicon (Si) and germanium (Ge) and it becomes much more complicated in compound semiconductors and oxides. Vapour phase decomposition inductively coupled plasma mass spectrometry or total reflection X-ray fluorescence techniques, which are usually used for the contamination analysis of Si wafers in modern microelectronics, cannot detect low concentrations of defects and those in the bulk of crystals. These techniques cannot also determine whether the defects are electrically active, and, therefore, other experimental methods should be used. Herein, based on the example of several common contaminations (transition metals, hydrogen, and sodium) we perform the extensive analysis of electrically active defects in SiO2 and Si by using contactless surface photovoltage measurements (SPV) impedance measurements, and deep level transient spectroscopy measurements (DLTS) together with its high-resolution Laplace DLTS modification. We demonstrate that such an analysis may give information not only about the electrical properties of defects and their concentration but also about their nature. We also show that SPV and electrical measurements could be successfully used for the determination of the electrical and structural properties of defects in high-k oxides and compound semiconductors.
A.I.Dagman Novolipetsk Steel PJSC (NLMK), Russia
Effective technology for the production of hot rolled and cold rolled high-strength low-alloy steels
Study of metal samples taken from 9 pilot batches of semifinished hot-rolled products for the manufacture of cold-rolled HC340LA steel annealed in bell furnaces was carried out for steel of 2 melts of different compositions with Nb or Ti microalloying. Methods of light and electron microscopy, local X-ray analysis, and testing of mechanical properties were used. It was found the experimental steel is characterized by a low content of non-metallic inclusions (NMI) and high metallurgical quality. In Nb microalloyed rolled steel elongated (rolled) MnS precipitates dominate. Globular precipitates are quite rare, as well as oxide inclusions. In terms of the degree of desired dispersion and spheroidization of sulfide precipitates, Ti microalloyed steel has an advantage.
Nb microalloyed rolled steel is characterized by structural and grain size inhomogeneity. The grain size in the axial zone of the rolled product is larger than near the surface, which is associated with the patterns of the reverse redistribution of components and the microstructure formation during hot rolling. In steel with Ti, there is a uniform microstructure.
Thus, a number of new significant scientific and technical results have been obtained. According to the developed technology, it is possible to simultaneously produce semifinished hot-rolled product for the manufacture of HC340LA cold-rolled steel annealed in bell-type furnaces and S420MS hot-rolled product with improved indicators of structural state and properties, while reducing costs. From a technical and economic point of view, it is preferable to use steel microalloying with Ti instead of Nb. The possibility of continuous casting of Ti microalloyed steel after Nb microalloyed steel at the same tundish has been established.
Madhu Gupta Delhi Pharmaceutical Sciences & Research University, India
Borrowing from nature: Skin Inspired Biomimetic Hydrogels to Promote Chronic Wound Healing
Chronic, non-healing diabetic wounds put a massive economic burden on health services causing patient incompliance and discomfort. Thorough interpreting of chronic wound pathophysiology led to the fabrication of targeted systems of drug delivery that can improve and accelerate the wound healing process. Natural polymers or biopolymers are now explored for the fabrication of wound dressings. Polysaccharides elicit enormous and promising applications due to their extensive obtainability, innocuousness, and biodegradability. Various outstanding features of polysaccharides can be employed to fabricate biomimetic and multifunctional hydrogels as efficient wound dressings. These hydrogels mimic the natural extracellular matrix and also boost the proliferation of cells. Owing to distinctive architectures and abundance of functional groups, polysaccharide-derived hydrogels have exceptional physicochemical properties and unique therapeutic interventions. Hydrogels designed using polysaccharides can effectively safeguard wounds from bacterial attack. More research is required to engineer multifaceted advanced polysaccharide hydrogels with tuneable and adjustable properties to attain huge potential in wound healing. Chitosan- based hydrogels demonstrated better healing as they inhibited bacterial growth and expedited re-epithelization and cell proliferation. So, these hydrogels can be used for effective wound care offering truly valuable material in the field of wound healing and certainly opening new avenues for future research and development.
Lawrence Kulinsky University of California, United States
Directed Electrokinetic Micro- and Nano-Assembly of Polymer Microbeads, Carbon Nanotubes, and Biological Cells
Assembly of microdevices from constituent parts currently relies on slow serial steps via direct assembly processes such as pick-and-place operations. Template Electrokinetic Assembly (TEA), a guided, non-contact assembly process developed by a research group at the University of California, Irvine, is a promising alternative to serial assembly processes. To characterize the process and its implementation of electrokinetic dielectrophoretic and electroosmotic phenomena, studies were conducted to examine the assembly of polymer microparticles at specific locations on glassy carbon interdigitated electrode arrays (IDEAs). The IDEAs are coated with a layer of lithographically patterned resist, so that when an AC electric field is applied to the IDEA, microparticles suspended in the aqueous solution are attracted to the open regions of the electrodes not covered by photoresist. Interplay between AC electroosmosis and dielectrophoretic forces guides 1 m and 5 m diameter polystyrene beads as well as biological cells to assemble in regions, or “wells,” uncovered by photoresist atop the electrodes. Additionally, dielectrophoretic nanoassembly can be used to heal and repair damaged microelectrodes. A novel method of electrode healing using electrokinetically assembled carbon nanotube (CNT) bridges is presented. Utilizing the step-wise CNT deposition process, conductive bridges were assembled across ever-larger electrode gaps, with the width of electrode gaps ranging from 20 microns to well over 170 microns. This work represents a significant milestone since the longest electrically conductive CNT bridge previously reported had a length of 75 microns. Connecting electrodes via conductive CNT bridges can find many applications from nanoelectronics to neuroscience and tissue engineering.
Eliane Trovatti University of Araraquara, Brazil
Crosslinking starch with Diels–Alder reaction: water-soluble materials and water-mediated processes
Click chemistry is extensively used for the development of biosensors and diagnostic tools, medicines and vaccines, among other technologies. The chemical methods for bioconjugation uses mild condition reactions, such as pH closed to neutral, temperature around environment or the body temperature, and uses water as the universal solvent, aiming to enable the reaction to be carry out under physiological conditions. The reactions are normally site-specific, and most of them are related to derivatization of proteins, DNA, RNA, and carbohydrates. Several chemical strategies have been developed in order to increase the range of bioconjugation reactions and to improve the singularities of those which are already in use. Among the click chemistry reactions, Diels–Alder cycloaddition is a one-step high-yield reaction that does not require catalysts, does not generate side products and can be performed at mild conditions in an aqueous medium, representing a good method for biomaterials coupling and synthesis. It exploits functional groups that can be grafted onto natural polymers or other molecules and can be used for the preparation of biomaterials such as biocompatible hydrogels. If performed in an aqueous medium, at biological pH and body temperature, it can be used in internal body systems for drug and cell release. Here we report the grafting of the furan ring from furfuryl alcohol to chemically oxidized starch and its crosslinking via the Diels–Alder reaction, in aqueous medium, mimicking the body conditions in vitro. Since the functional groups used in this chemical strategy are sparingly studied for such applications, the biocompatibility of the crosslinked starch as well as that of the precursor reagents were evaluated by cytotoxicity tests using GM07492 human cells. The results reveal that the furan-crosslinked starch is a promising candidate for cell encapsulation and delivery within the body.
Chun-Yun Wang University of Stuttgart, Germany
Discovery of single white emitters for white LEDs
White LEDs have been widely used in lighting and displays, owing to their high energy efficiency, small size, long lifetime and environmentally friendliness. To generate white light, a UV/near-UV LED chip combined with multiple colors emitting phosphors can reach a better color stability and higher color rendering index than a blue LED chip combined with a yellow-emitting phosphor. However, the former type LED has a higher cost and the reabsorption among different emitting phosphors will reduce the efficiency. An ideal option would be a single white-emitting phosphor combined with a UV/near UV LED chip. Therefore, the development of a single-phase white-emitting phosphor is urgently required and highly challenging.
Here, I will present our recent discovery of two white-emitting phosphors: a Ce doped new sialon compound (Ba,Sr)4-mLi(Si,Al)19+2m(O,N)29+m  and a (Bi,Ce)-codoped lead-free perovskite Cs2Ag0.4Na0.6InCl6, shown in Fig. 1. (Ba,Sr,Ce)4-mLi(Si,Al)19+2m(O,N)29+m is a rare occasion of a single activator white-light-emitting phosphor, and the first Ce-doped sialon-based one to be reported. After UV light excitation, it results in white light emission due to a double broad-band emission with peaks around 465 and 625 nm. (Bi,Ce)-codoped Cs2Ag0.4Na0.6InCl6 has a high quantum yield of 98.6%, and a white LED with high performance (CRI = 95.7; CCT = 4430 K) has been achieved. We investigated deeply the relationship between crystal structure and photoluminescence properties and elucidated the luminescence mechanism. Our discovery will give a novel insight into the design of new single white emitters.
Seungpyo Hong University of Wisconsin, United States
Exosome-dendrimer Hybrid Nanoparticles for Effective Delivery of Combination Therapeutics
Nanoscale drug delivery systems for cancer treatment have demonstrated promising results in enhancing the selectivity of therapeutic agents while reducing their toxic side effects. However, several biological and physical barriers, such as the immunogenicity and undesirable biodistributions of such delivery systems, have hindered their fast translation. To address these issues, we have developed an exosome-dendrimer hybrid nanoparticle (NP) platform to combine the advantageous biological properties of natural exosomes and synthetic dendrimers into a single NP system. The novel hybrid NPs, consisting of exosomes derived from MCF7 cells and functionalized poly(amidoamine) (PAMAM) dendrimers, were prepared using sonication and characterized in terms of loading efficiency, size, cytotoxicity, and cellular interactions. Our results indicate that the loading of dendrimers into exosomes is dependent on dendrimer size and charge. The hybrid NPs inherited the size (~150 nm), surface charge (-10 mV), and surface protein markers (CD81, CD63) of exosomes. Importantly, the hybrid NPs enhanced cellular internalization of amine-terminated PAMAM dendrimers (p < 0.05), while exhibiting substantially lower cytotoxicity than the free positively charged dendrimers (113.3% vs. 35.6% of cell viability at 500 nM, p < 0.05). These advantageous properties of hybrid NPs were leveraged for use as a gene delivery vehicle, resulting in enhanced oligonucleotide delivery (over 2-fold) to cancer cells, compared to dendrimers alone. Furthermore, hybrid NPs effectively delivered small interfering RNA (siRNA) as well, downregulating programmed death-ligand 1 (PD-L1) expression significantly more (3.8-fold) than dendrimers alone (p < 0.05). Our results demonstrate that the individual characteristics of both exosomes and dendrimers can be integrated to generate a multifaceted NP platform, proposing a novel NP design strategy.
Patricia E. Oliveira Catholic University of Temuco, Chile
Green Solutions for Food and Health from Invasive Species: Unveiling the Antioxidant and Antimicrobial Power of Chusquea quila and Ulex europaeus
The study aimed to investigate the antioxidant and antimicrobial properties of Chusquea quila and Ulex europaeus. The primary objectives were to explore their potential in the food industry and evaluate their antioxidant capabilities in wastewater. A literature review was conducted to gather information on extraction methods, and a laboratory protocol was developed using ethanol to extract bioactive compounds and assess their efficiency, total phenolic content, antioxidant activity, and anthocyanin levels.
Results showed that ethanol extraction was most efficient for Chusquea quila stem (10.95%) and acetone extraction was most effective for the leaf (11.27%). For Ulex europaeus, acetone extraction yielded the best results for the stem (11.3%), while hydrodistillation and methanol extraction from the branch (flower) registered positive outcomes (11.26% and 10.57%, respectively). Further analysis of the ethanol extracts revealed higher phenolic compound concentrations in Chusquea quila leaf (28.43 mg/100gPS) and Ulex europaeus leaf (flower) (38.27 mg/100gPS). Both species displayed consistent antioxidant activity, with an average of 2.7 AA or RSA (mg of Trolox Eq/gPS). Anthocyanin content was also quantified, with 0.84 mg of cyanidin-3-O-glycoside found in Chusquea quila leaf and 1.11 mg in Ulex europaeus branch.
These findings indicated that both Chusquea quila and Ulex europaeus possessed antioxidant properties characterized by their phenolic and anthocyanin content. The study suggested their potential application in the functional food industry, contributing to the mitigation of health risks associated with rodents and addressing ecological disturbances such as competition and the risk of wildfires. Furthermore, the antimicrobial activity of the extractable compounds was evaluated. Sensitivity tests on agar plates demonstrated antimicrobial properties, with the Ulex europaeus flower extract at a 10% concentration showing the largest inhibition zone diameter (19.91 mm).
Maria Piernas CIC EnergiGUNE, Spain
Deeper insights into the conversion reaction of Prussian blue in Li-ion batteries
Although widely studied as cathodes, Prussian blue and analogues have also emerged in the last decade as potential anode materials for lithium-ion battery applications. Large capacities and fairly good performance at high current densities are some of their properties to highlight when electrochemically cycled vs. metallic lithium in a low voltage window. ,
Based on the Prussian blue analogue formula AM[M’(CN)6], where A is generally an alkali ion, and M and M’ are metals in oxidation state +3 and +2 (being M’ generally Fe), respectively, one would expect the reduction of M from +3 to +2 and the subsequent oxidation of both M and M’ from +2 to +3. However, the high-capacity values they exhibit suggest the occurrence of a further reduction.
Some years ago, we reported a study proposing a “conversion reaction” for this type of materials as the most plausible explanation for releasing such a high capacity, considering the evidence obtained for purely iron Prussian blue, KFe[Fe(CN)6], by different techniques, which include ex-situ X-ray diffraction, infrared and, transmission electron microscopy.
Recently, we have confirmed the formation of Fe0 nanoparticles using ex-situ X-ray absorption and in operando Mössbauer spectroscopies and, elucidated the reaction mechanism, which surprisingly would involve two intermediates iron species in the unusual +1 oxidation state.
Ke Wang University of Minnesota, United States
Quantum Controls of Electrons in 2D Nanostructures
Since the discovery of graphene via mechanical exfoliation, it has been shown that the electronic properties of solids can undergo dramatic change when the material thickness is reduced to the atomic limit. Their exotic bandstructures are uniquely different from those in conventional 2DEGs. The relativistic charge carriers in monolayer graphene can be manipulated in manners akin to conventional optics, leading to electronic device concepts analogous to optical circuits (electron-optics). In this talk, we will discuss about novel gate-defined nanostructures in graphene, which recently allowed us to demonstrate controlled electron-optic interference process at zero magnetic field as a consequence of consecutive Veselago refractions, and generation of highly- collimated and valley-polarized electron current.
Environmental Conservation by using Algerian Clays in phenolic compounds removal from wastewater
Phenolic compounds are considered persistent pollutants even at low concentrations by the Environmental Protection Agency (EPA). The limit values of phenolic compounds must not exceed 12 μg/l. Phenolic compounds exist widely in many industrial effluents and are among the most common organic pollutants in water because of their high toxicity, even at low concentrations.
To tackle these problems, researchers have performed oxidation and adsorption onto clay as an effective and alternative process that can be used in wastewater treatment. The valorization of clay as a catalytic decontamination material is to promote the degradation of a specific organic pollutant because it is very abundant and low-cost.
Our works focused on the application of Algerian clay (Sodium Clay SC) for the adsorption and the oxidative degradation of cresols (o-Cresol in our case) as one of the most phenolic pollutants.
Jose Luis Diaz De Tuesta Universidad Rey Juan Carlos, Spain
3D-printed carbonaceous materials as catalysts for the removal of micropollutants from simulated matrices
Recent research has focused on developing efficient and sustainable materials for wastewater treatment technologies such as adsorption, membrane filtration, electrochemical technologies, and advanced oxidation processes. Among them, carbon-based materials (e.g. activated carbon, carbon nanotubes or graphene) have demonstrated high adsorption capacity, catalytic activity and electrical conductivity to be successfully used in those processes. However, the assembly of carbon structures to be efficiently used as flat electrodes, monoliths or pellets keeping the original physicochemical properties of powdered carbon materials remains a challenge. Recently, we prepared 3D-printed carbonaceous materials by stereolithographic 3D printing using a resin comprised of monomers (pentaerythritol tetraacrylate and divinylbenzene), porogen (2-ethylhexyl), photoinitiator (2,4,6-trimethyl benzoyl), and a die (Sudan-I). The 3D printed structure underwent Soxhlet extraction to remove the die, stabilized by a thermal treatment in the air (at 573 K for 6 h), and pyrolyzed in N2 (at 1173 K for 0.3 h) to finally obtain the M11 sample. This material was further activated with CO2 (1133 K) to obtain the M14 sample. The results indicate that the surface area increased from 409 m2 g-1 (M11) to 869 m2 g-1 after the CO2 activation step (M14). The materials have been successfully applied in the catalytic wet peroxide oxidation of micropollutants at trace levels, 80 °C, initial pH 3.5, and using stoichiometric amounts of H2O2 for complete pollutant mineralization. Oxidation experiments revealed that both samples have activity in CWPO, overcoming the results obtained in non-catalytic runs. Moreover, the reaction using M14 as a catalyst revealed a strong influence of adsorption-desorption mechanisms due to increased catalyst surface area, a behavior not reported in other studies.
Pedro Tavares Universidade NOVA de Lisboa, Portugal
Protein nanocages structural dynamics and DNA interaction
Protein nanocages are biologically designed to provide compartmentalization towards enzyme catalyzed reactions, storage, delivery, and protection. Usually built from dozens to hundreds of equal or highly similar subunits, these nanocages can be described as porous protein shells (with thickness of 1 to 3 nm) with a variable size inner cavity.
In this study we look to the structural dynamics and DNA binding characteristics of two prokaryotic nanocages.
A new class of compartments, named encapsulins (Enc), was recently identified. Their main feature is that they can encapsulate specific cargo proteins, which are targeted to the lumen via a short peptide extension at the C-terminus, that, in most cases, serves as an anchor to the shell. Most encapsulins assemble into T = 1 (60 subunits, 20-24 nm in diameter) or T = 3 (180 subunits, 30-40 nm) icosahedral hollow cages. The biological role of these encapsulation systems is yet to be unveiled. Our work shows that encapsulin can bind to circular double stranded DNA, eliciting physical protection from enzymatic digestion by DNase I.
DNA-binding proteins from starved cells (Dps) are small multifunctional nanocages expressed in acute oxidative stress conditions. Dps proteins protect bacterial DNA from damage by either direct binding (promoted by unordered, flexible, N- and/or C-terminal extensions) or by removing precursors of reactive oxygen species from solution. In a series of works we show that the N-terminal extensions can assume extended and compact conformations modulated by the ionic strength and/or divalent metal ions in a reversible and controlled manner. Such structural dynamics can be part of a regulatory process for Dps-DNA interaction.[4,5]
An-Ya Lo National Chin-Yi University of Technology, Taiwan
Enhancement of Mesoporous Photocatalyst with Lewis Acid Sites for Enhanced CO2 Photoreduction
We developed and optimized a mesoporous photocatalyst for CO2 photoreduction (CO2PR) by integrating TiO2 with a CMK-3 template. Silver (Ag) doping strategies were studied using photodeposition and synchronous doping. Our investigation revealed that Lewis acid sites had the greatest influence on CO2PR efficiency and product selectivity, followed by Lewis base sites and charge-carrier recombination rates. This is because Lewis acid sites controlled H+ production and hence influence CO and CH4 production rates and selectivity. We demonstrated the irradiation-induced acid/base behavior of the photocatalyst using NH3-/CO2-temperature programmed desorption. Our engineered photocatalyst, S-Ag1.0TC470, exhibited 96% CH4 selectivity and an 11-fold higher production yield than commercial P25. Ag-doping had limited effect on the band structure, and its contribution was mainly related to acidity/basicity. The Ag+ ions in S-Ag1.0TC470 acted as Lewis acid sites, improving H2O dissociation and enhancing H+ ion production. Lewis acid sites played a crucial role in driving the reaction towards higher CH4 selectivity. Photocatalysts with fewer Lewis acid sites showed limited yield/selectivity, despite abundant Lewis base sites. Mesoporous TiO2 prepared with CMK-3 template and TiSO4 precursor demonstrated higher CO2PR performance. The optimized calcination temperature was 470 °C for CMK-3 removal. Synchronous doping with Ag2+ ions resulted in a photocatalyst (S-Ag1.0TC470) with stronger Lewis acid sites under irradiation, achieving 96% CH4 selectivity and an 11-fold higher production yield compared to P25. Our findings highlight the importance of Lewis acid sites in photocatalysts for CO2PR and provide insights for future photocatalyst design. The proposed approach can be applied to engineer and optimize similar photocatalysts for CO2 photoreduction.
Yuhang Jing Harbin Institute of Technology, China
A machine-learning interatomic potential to understand primary radiation damage of silicon
Harsh radiation environments cause displacement damages in semiconductor components, resulting in performance degradation. Molecular simulations provide a unique approach to study the dynamic processes of radiation-induced defect production, clustering, and evolution to design and reinforce novel semiconductor components. In this paper, we developed a more efficient machine learning (ML) potential with density functional theory (DFT) accuracy to investigate the radiation damage in silicon material. We constructed a large DFT dataset containing conformations related to static properties, point defects, amorphous phases, and radiation damage. Then, we use ML methods to learn the difference between the DFT and the short-range interaction. The final model is made up of a ML potential and a short-range interaction component. The accuracy of the potential was verified by comparing the static properties, defect formation energy, and threshold displacement energy with experiments and DFT data. Then, based on the ML potential, we investigated defect production, clustering, and evolution using a single PKA excitation. We found that based on the empirical potentials, the effect of PKA is more localized. In contrast, based on the ML potential, it has an impact over a larger spatial area. The defects generated by the ML potential are still dominated by isolated defects, and there are also some medium and large defect clusters. Finally, we studied the sequential excitation of the PKAs. We found that the first several PKAs produce an amorphous region, while the later PKAs first pass through the amorphous regions and then produce defects at greater depth. Due to the dissipation of kinetic energy while going through the amorphous region, the later excited PKAs produces fewer defects. Therefore, it is necessary to consider the case of sequentially PKA excitations in atomic simulations for radiation damage.
Zhaoru He Nanjing University of Aeronautics and Astronautics, China
Uncovering the roles of laser action modes in surface mechanical propertiesof 2024 aluminum alloy
The surface state/performance after laser action is as essential as the interplay mechanism between laser and material. Through the designed experiments, the effect of distinct laser action modes on the evolution mechanism of aluminum alloy surface’s microstructure and mechanical property was discussed. Under laser-induced thermal effect, the procedure of “vaporization-plasma plume-recoil effect-solidification” occurred. The grains grew longitudinally with an average size of 13.49 μm, which is smaller than that of substrate. Under the thermal oxidation, new oxides were formed. However, laser-induced force effect did not purpose a change in the composition. Importantly, force effect refined the grains to an average grain size as low as 6.21 μm. Notably, ananomaly was discovered. The thermal effect produced stress concentration that increases the residual stress by 64.7%, which caused the hardness to rebound. Additionally, surface composition and microstructure evolutionled to the first decrease and then increase of friction coefficient. Due to grain refinement and residual stress induced by force effect, the hardness improved continuously and the friction coefficient decreased continuously. Understanding the influence mechanism of laser action modes on surface structure/property can furnish theoretical guidance for development of laser processing technology in the industrial field.
Ryota JONO Research Organization for Information Science and Technology, Japan
On the shear-thickening event of the spherical bodies: a non-equilibrium molecular dynamics study
We studied the shear-thickening behavior of systems containing rigid spherical bodies immersed in smaller particles using non-equilibrium molecular dynamics simulations. The viscosity (η) at a given shear rate (γ ̇) is expressed as η(γ ̇ )=-〈P_xy 〉/γ ̇, where 〈P_xy 〉 is the ensemble average of the pressure tensor element P_xy. The standard deviation of η depends on shear rate γ ̇ because that of P_xy does not depend on the shear rate. The standard deviation of η is sufficiently small for γ ̇ values larger than 108 s−1. Therefore, it is important to find the conditions under which shear thickening occurs at γ ̇ = 108 s−1. It has been reported that shear thickening occurs when the Péclet number, Pe=γ ̇a^2/D, is approximately 100, where a is the representative length and D is the diffusion coefficient of the system. Based on this rule of thumb, we multiplied the mass of the particles by 106 because the diffusion coefficient should be modified from ~10−9 m2 s−1 to ~10−11 m2 s−1 considering the diameter of regular dodecahedrons (~1 nm) as the representative length, and the applied shear rate was ~108 s−1. Then, we generated shear-thickening states through particle mass modulation of the systems. The microstructures, i.e., two-dimensional pair distribution functions of the systems at the critical shear rate were analyzed, and we found anisotropic structures resulting from shear thickening, that is explained by the difference between the velocities of rigid bodies and fluid particles. The increasing viscosity in our system originated from collisions between fluid particles and rigid bodies.  Based on the results we studied the effect on the critical shear rate from the mass of the particles, the concentration of the particles, and the temperature of the systems.
Jiangwei Liu National Institute for Materials Science (NIMS), Japan
Deposition and mechanism study for super-high dielectric constant AlOx/TiOy nanolaminates
Super-high dielectric constant (k) AlOx/TiOy nanolaminates (ATO NLs) are deposited by an atomic layer deposition technique for application of next-generation electronics. Individual multilayers with uniform thicknesses are formed for the ATO NLs. With the increase of AlOx content in each ATO sublayer, the shape of Raman spectrum has a tendency to close to that of the single AlOx layer. Effects of ATO NL deposition conditions on electrical properties of the metal/ATO NL/metal capacitors are investigated. Lower deposition temperature, thicker ATO NL, and lower TiOy content in each ATO sublayer can lead to lower leakage current and smaller loss tangent at 1 kHz for the capacitors. Higher deposition temperature, larger number of ATO interface, and higher TiOy content in each ATO sublayer are important to obtain higher k values for the ATO NLs. With the increase of resistance for the capacitors, the ATO NLs vary from semiconductors to insulators and their k values have a decrease tendency. For most of the capacitors, the capacitances reduce with the increment of absolute measurement voltage. There are semi-circular shapes for impedance spectra of the capacitors. By fitting them with the equivalent circuit, it is observed that with the increase of absolute voltage, both parallel resistor and capacitance decrease. The variation of the capacitance is explained well by a novel double-Schottky electrode contact model. The formation of super-high k values for the semiconducting ATO NLs is possibly attributed to the accumulation of depletion charges.
Oreste De Luca Università della Calabria, Italy
New insights in polydopamine formation via surface adsorption
Polydopamine is a biomimetic self-adherent polymer, which can be easily deposited on a wide variety of materials1,2. Despite the rapidly increasing interest in polydopamine-based coatings, the polymerization mechanism and the key intermediate species formed during the deposition process are still controversial. Herein, a systematic investigation of polydopamine film formation on the nanometer-sized surface of halloysite nanotubes is reported. The negative charge and high surface area of halloysite nanotubes favour the capture of intermediates that are involved in polydopamine formation and decelerate the kinetics of the process, to unravel the various polymerization steps. Data from X-ray photoelectron and solid state nuclear magnetic resonance spectroscopies demonstrate that in the initial stage of polydopamine deposition, oxidative coupling reaction of the dopaminechrome molecules is the main reaction pathway that leads to formation of polycatecholamine oligomers as an intermediate and the post cyclization of the linear oligomers occurs subsequently. Furthermore, TRIS molecules are incorporated into the initially formed oligomers, while the presence of this molecule becomes less important as the reaction time proceeds.
Jianxin Zou Shanghai Jiao Tong University, China
Preparation of Mg-based nano heterostructure composites for enhanced hydrogen storage properties
Hydrogen has been considered as a potential candidate to replace fossil fuels, due to its high gravimetric energy density, high abundance, and environmental-friendliness. However, owing to its low volume density, effective and safe hydrogen storage techniques are now becoming the bottleneck for the "hydrogen economy". Under such a circumstance, Mg-based hydrogen storage materials garnered tremendous interests due to their high hydrogen storage capacity (~7.6 wt.% for MgH2), low cost, and excellent reversibility. However, the high thermodynamic stability (ΔH = -74.7 kJ/mol H2) and sluggish kinetics result in a relatively high desorption temperature (>300 oC), which severely restricts widespread applications of MgH2. Nano-structuring has been proven to be an effective strategy that can simultaneously enhance the ab/de-sorption thermodynamic and kinetic properties of MgH2, possibly meeting the demand for rapid hydrogen desorption, economic viability, and effective thermal management in practical applications. It has been established that the addition of two dimensional (2D) materials into MgH2 is efficient in improving its hydrogen storage performances.
2D transition metal carbides (such as Ti3C2) and oxides (such as TiO2 nanosheets) exhibit some potential advantages for the modification of hydrides. Herein, based on the previous studies of Mg-based hydrogen storage materials and the special structure of 2D materials, we have conducted three approaches to improve the hydrogen storage properties of MgH2 via building muti-phase catalyst/composite (Ni/Co@Ti-MX, In@Ti-MX) or nanoconfinement by using single/few-layer Ti3C2 MXene (MgH2@Ti-MX) and TiO2 nanosheets (MgH2/TiO2). The resulting MgH2-2D material composites exhibit some improved hydrogen storage properties. The in-situ high resolution TEM observations of the decomposition process together with other analyses revealed that the nano-catalyzing and/or nano-confinement effects were main reasons accounting for the lower hydrogen sorption temperatures and excellent cyclic stability. These studies not only provide a new strategy to improve the hydrogen storage properties of MgH2, but also gives an inspiration to develop other high performance hydrogen storage systems.
Farshid Jamshidi Karlsruhe University of Applied Sciences, Germany
Geometric flow control in lateral flow assays
Lateral flow assays (LFAs) are widely used in diagnostic applications such as COVID-19
rapid tests and pregnancy tests. LFAs consist of porous membranes in which the diagnosis
fluid flows. The geometry of these membranes and their profile strongly affect the
functionality and performance of the LFAs. To investigate the effect and to derive
correlations, a comprehensive sensitivity analysis is carried out, starting with the
development of a single-phase model based on the Darcy equation to represent the fluid
dynamics within LFAs. Different membrane profiles such as straight, barbell, hexagonal,
sand timer, and T-shaped geometries are systematically investigated to gain an in-depth
understanding of their influence on the propagation of the fluid front, known as the wicking
behavior. The model accurately predicts the dynamics of the fluid flow and a remarkable
agreement between the model predictions and the experimental imaging data is observed,
confirming the accuracy of the model in representing the wicking processes. This agreement
highlights the significant potential of the model in controlling and manipulating wicking
processes to achieve desired velocities at specific locations within LFAs. Furthermore, a twophase
model utilizing the IMplicit Pressure Explicit Saturation (IMPES) algorithm is
developed and used to simulate the observed wicking behavior in LFAs. The results obtained
by the model show a robust correlation with the experimental data, further supporting the
feasibility of manipulating the wicking processes and facilitating the development of tailormade
membranes for specific diagnostic applications. We conclude that the agreement
between the modelling results and experimental observations could serve as a basis for the
precise control and optimization of wicking processes, thus promoting the development of
application-oriented membranes capable of improving the performance and efficiency of
LFAs in various diagnostic applications.
Ipsita A. Banerjee Fordham University, United States
Design of Peptide-Conjugates for Targeting the EGFR Receptor and its Mutants
The epidermal growth factor receptor (EGFR) belongs to a family of tyrosine kinases (RTKs) which plays a crucial role in cellular processes such as cell proliferation, differentiation and migration.1 However, its overexpression has been implicated in several types of cancers due to unregulated activity of downstream MAPK signaling pathways.2 Furthermore, certain carcinomas including those seen in lung cancer develop mutations such as T790M/L858R and V948R causing chemo-resistance which makes treatment more difficult.3 Thus, it is imperative to not only decipher the binding interactions of these mutated receptors, but also develop new drug candidates that may be potentially applicable for therapeutics not only toward the EGFR wild-type but also mutant receptors. In this work, we have designed a series of novel peptide-based conjugates to elucidate the binding interactions and targeting ability of those conjugates. We investigated the binding interactions computationally using docking and molecular dynamics studies. We then synthesized some of the conjugates, and examined their interactions with tumor cells overexpressing the receptors in order to further validate the results.
Sami Ramadan Imperial College London, United Kingdom
Graphene sensor arrays for rapid and accurate detection of pancreatic ductal adenocarcinoma cancer exosomes in plasma samples
Pancreatic cancer (PC) is the second deadliest cancerous disease with a poor survival prognosis. However, the survival rate can be significantly improved if the cancer is detected at an early stage. Liquid biopsies that use novel biomarkers such as circulating tumour DNA, circulating tumour cells, exosomes, and microRNAs presented in body fluids have emerged as promising approaches for early diagnostics of PC. Among them, exosomes which are small extracellular vesicles (30-150 nm), are released in high quantities by healthy and tumour cells, enabling cell-to-cell communication. It is suggested that exosomal Glypican-1 (GPC-1) is a potential biomarker for the detection of PC. Here, we demonstrate an accurate and robust portable graphene-field-effect (GFET) array biosensor platform for the detection of pancreatic ductal adenocarcinoma (PDAC) in patients’ plasma through specific exosomes (GPC-1 expression) within 45 minutes. Based on samples from 18 PDAC patients and 8 healthy controls, the GFET biosensor arrays could accurately discriminate between the two groups, while being able to detect early cancer stages including grades 1 and 2. Furthermore, we confirmed the higher expression of GPC-1 and found that the concentration in PDAC plasma was more than one order of magnitude higher than in healthy samples. We found that these characteristics of GPC-1 cancerous exosomes are responsible for an increase in the number of target exosomes on the surface of graphene, leading to an improved signal response of the GFET biosensors. Thus, this GFET biosensor can be considered a powerful and promising diagnostic tool for detecting PC and other types of cancer and disease biomarkers.
Ulrich Müller BOKU - University of Natural Resources and Life Sciences, Austria
THE POTENTIAL OF WOOD FOR THE AUTOMOTIVE ENGINEERING OF THE FUTURE
The current discussion about the carbon footprint of future vehicles requires the use of bio-based materials for automotive construction. Modern wood composites are one of the most promising materials for this purpose. They are characterized by excellent mechanical properties at comparatively low density. However, material data, material models and reliable material cards of wood are not yet available for finite element modelling under dynamic loading and in crash situations, which are, however, absolutely necessary for use in the context of component design and construction.
As an example of the work done so far, consider the development of a side impact beam for a conventional passenger car. The original component of the vehicle under investigation is made of ultra-high strength steel. For the benchmarking of the developed side impact beam, crash tests according to the US NCAP consumer protection pole test were carried out and compared with the convential steel element. The beam developed was around 25 % lighter and delivered comparable values to the original component in terms of the required penetration depth and energy absorption. Among other applications, a wood hybrid battery case, a staircase for a coach and a chassis for an electrically driven tracked vehicle were examined.
In all cases, the lightweight construction potential of wood could be demonstrated. Furthermore, it could be shown that the FE modelling of such structures has a high prediction quality even in the crash case.
Dennis G. Drescher Wayne State University, United States
Protein interaction analysis by surface plasmon resonance
Surface plasmon resonance (SPR) is an optical technique utilized for detecting molecular interactions. Binding of a mobile molecule (analyte) to a molecule immobilized on a thin metal film (ligand) changes the refractive index at the film surface. The angle of extinction of light reflected after polarized light impinges upon the film is altered and monitored as a change in detector position for the dip in reflected intensity. Because the method strictly detects mass, there is no need to label interacting components, thus eliminating possible changes of their molecular properties. One of the advantages in SPR is its high sensitivity, particularly when only small amounts of pure protein are available. Binding affinities can be obtained either from the ratio of rate constants or from measurement of the steady state level of binding as a function of binding-partner concentration (typically 1-250 nM). We have utilized SPR to study interaction of ferlin proteins. Representatives of this group include dysferlin, required for the continuous repair of skeletal muscle, and otoferlin, necessary for hearing by triggering calcium needed for synaptic transmission. We determined the binding strength and calcium dependence of direct interactions between dysferlin and proteins likely to mediate skeletal muscle repair in LGMD2B muscular dystrophy. Dysferlin interacts via its carboxy terminus with FKBP8, an anti-apoptotic outer mitochondrial membrane protein, and via its C2DE domain with apoptosis-linked PDCD6, linking anti-apoptosis with apoptosis. Otoferlin interacts with the auditory sensory-cell calcium channel, as well as with two main target-SNARE proteins of the receptoneural synaptic complex, syntaxin 1A and SNAP-25, via its C2F and C2D domains. With amino-acid mutations in otoferlin as seen in DFNB9 deafness patients, interactions are greatly diminished. SPR thus serves as a useful tool to examine molecular mechanisms of genetic disorders of muscle and inner ear.
Rodney Herring University of Victoria, Canada
Imaging the core of dislocations and their annihilation at crystal surfaces
Since the beginning of electron microscopy, the core of dislocations, a major defect in three dimensional (3D) crystals affecting all their physical properties, eluded imaging by all means including diffraction contrast and lattice imaging. Contrast by diffraction occurs to one side and away from the dislocation and lattice imaging is 2 dimensional of a 3D structure. A successful means has been achieved by interfering symmetrically Bragg diffracted beams to obtain the phase information passing through the core of the dislocation. The phase measures the strain of dislocations enabling to see their interactions. At the free surface, the dislocation transforms from a one dimensional to a 3D structure. The dislocation core has a 2 phase shift representing one atomic plane over a 360o rotation, i.e., the Burgers vector (B), producing possibly the smallest physical singularity. Close to the free surface, the dislocation is seen to destabilize forming a triple point, also a singularity, at the base of a 3D structure most likely formed by the creation and intersection of three surfaces. A mechanism is the dislocation splitting into two dislocations of different B as commonly found in fcc materials. These dislocations cross-slip onto adjacent, allowed planes and then fault via partial dislocations to create three connected surfaces, which reduces their formation energy by 1/2B*E, where E is the (theoretical) elastic modulus. Relaxation of the three surfaces by the remaining strain energy, i.e., 1/2B*E, ejects an atom onto the surface to nucleate the formation of the pit. The formation energy in gold was measured to be 1.6 nN. Questions arise. Which singularity is smaller, the dislocation core’s or the triple point of the 3d structure? Additionally, is this imaging method able to see and measure the existence of dopants and electrical charges that theoretically exist in/at the core of dislocations?
Chieko Kuji Tohoku University, Japan
Effect of microstructure of amorphous alloys on micro-regional mechanical properties
Amorphous alloys are non-equilibrium thin-strip alloys. While the amorphous structure improves magnetic properties dramatically, machining is extremely difficult due to its strong and tough properties. In this study, we developed a new machining method to improve machinability by controlling the microstructure of amorphous alloys and investigated the effect of microstructure on the micro-regional mechanical properties. Part of this work was supported by JSPS KAKENHI, grant number 23K13228, and The Amada Foundation, AF-2022238-C2.
Yiting Lei The First Affiliated Hospital of Chongqing Medical University, China
Injectable Self-Setting Ternary Calcium-Based Bone Cement Promotes Bone Repair
Bone defects, especially large ones, are clinically difficult to treat. The development of new bone repair materials exhibits broad application prospects in the clinical treatment of trauma. Bioceramics are considered to be one of the most promising biomaterials owing to their good biocompatibility and bone conductivity. In this study, a self-curing bone repair material having a controlled degradation rate was prepared by mixing calcium citrate, calcium hydrogen phosphate, and semi-hydrated calcium sulfate in varying proportions, and its properties were comprehensively evaluated. In vitro cell experiments and RNA sequencing showed that the composite cement activated PI3K/Akt and MAPK/Erk signaling pathways to promote osteogenesis by promoting the proliferation and osteoblastic differentiation of mesenchymal stem cells. In a rat model with femoral condyle defects, the composite bone cement showed excellent bone repair effect and promoted bone regeneration. The injectable properties of the composite cement further improved its practical applicability, and it can be applied in bone repair, especially in the repair of irregular bone defects, to achieve superior healing.
Tomás Barbosa da Costa Federal University of São João del-Rei, Brazil
Statistical learning and optimization of the helical milling of the biocompatible titanium Ti-6Al-7Nb alloy
Helical milling has been applied for hole-making in titanium alloys, especially in the Ti-6Al-4V alloy, considering the aims of the aeronautic, automobile, and other sectors. When considering hole-making in Ti-alloys for biomedical applications, few studies have been carried out. Besides, intelligent approaches for modeling and optimization of this process in these special alloys are demanded to achieve the best results in terms of hole surface quality, and productivity. This work presents an approach for modeling and optimization of helical milling for hole-making of Ti-6Al-7Nb biocompatible titanium alloy. The surface roughness of the holes was measured to quantify the hole quality. Principal component analysis was performed for dimensionality reduction of the roughness outputs. For modeling, a learning procedure was proposed considering polynomial response surface regression, tree-based methods, and support vector regression. Cross-validation is used for learning and model selection. The results pointed out that the support vector regression model was the best one. Multiobjective evolutionary optimization was performed considering the support vector regression model and the deterministic model of the material removal rate. The Pareto set and the Pareto frontier were plotted and discussed concerning practical aspects of the helical milling process. The proposed learning and optimization approach enabled the achievement of the best results of the helical milling in the biocompatible Ti-6Al-7Nb alloy and can be applied to other intelligent manufacturing applications.
Maria J. Ramalho University of Porto, Portugal
Smart nanoparticles for GBM therapy: an approach targeting MGMT-mediated resistance
Glioblastoma (GBM) is the most common and invasive type of brain cancer with high mortality. Its gold standard treatment is surgical resection followed by combination of radio and chemotherapy with the alkylating agent temozolomide (TMZ). However, the standard care is not curative, due to the tumour heterogeneity’s, anatomic location, high proliferation rate and intrinsic resistance mechanisms. O6-methylguanine-DNA-methyl-transferase (MGMT) protein is the most predominant resistance mediator in GBM, due to its ability to repair the drug-induced DNA damage. As the MGMT protein is overexpressed in about 40-60% GBM patients, approaches to circumvent these resistance mechanisms are urgent.
To overcome the resistance associated with the use of alkylating agents, we have explored three different strategies: (i) co-therapy of alkylating agents with MGTM inhibitors, bortezomib (BTZ) and O6-benzylguanine (O6BG); (ii) repurposing FDA-approved non-alkylating drugs, gemcitabine (GEM) and chloroquine (CHL); (iii) using natural compounds with anticancer properties independent of MGMT-resistance, asiatic acid (AA) and gallic acid (GA).
As the blood-brain barrier (BBB) represents a major challenge for drug delivery to the brain, in this work we propose engineered poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) able to cross the BBB and deliver the aforementioned compounds to the brain tumor.
All the prepared NPs were optimized by experimental design and exhibited optimal physicochemical features for brain delivery and controlled and sustained release. The uptake and antiproliferative effect of the developed NPs were evaluated in vitro using human GBM cells. The obtained results showed that the NPs are efficiently internalized by the GBM cells, promoting drug effects in inhibiting tumor cell survival and proliferation. Additionally, the biocompatibility of unloaded NPs was evaluated in human cells, demonstrating the safety of the developed NPs. Our findings prove that different approaches to circumvent the MGMT-mediated resistance may be suitable to treat GBM, overcoming the limitations of current therapeutic strategies.
Nikita Sharma University of Miskolc, Hungary
Demonstration of effectiveness: plant extracts in the tuning of BiOX photocatalysts' activity
The use of plant extracts, recently, has been extended to the field of photocatalysis and is reported as a “greener” route. It is called “greener” because it uses plant extracts as the main component which doesn’t produce any toxic compound. The present work deals with the synthesis of bismuth oxyhalides (Cl, Br, I) with three different plant extracts, namely, Camellia Sinensis, Azadirachta indica and Aloe barbadensis miller by a precipitation method for the removal of phenol under visible light. To clarify the effect of each plant extract, BiOX reference samples were prepared without plant extract. The samples were characterized for their structural, morphological, chemical and optical properties using XRD, SEM, FT-IR and DRS. Plant extracts, mainly, acted as structural and shape-tailoring agent as evident through a sharp decrease in the crystallite size and transformation of the plates-like morphology of BiOX. The photocatalysts BiOI with Azadirachta indica and BiOBr with Camellia Sinensis extract removed 87% and 82% of phenol, respectively, within 240 min. The role of organics coming from the plant extracts is discussed and significant correlations with the structural and optical properties were made to unfold the mystery of activity enhancement of the plant extract mediated BiOXs.
Sérgio S. Camargo Jr Federal University of Rio de Janeiro, Brazil
Experimental and computer simulation study of calcium carbonate surface scale deposition
Inorganic scale deposition is a major issue both from the fundamental and applied points of view. It affects several areas of industry, such as water distribution and treatment, desalination, energy generation, hydrometallurgy, and oil and gas, causing efficiency losses, flow blockage, and reducing the life span of the equipment. Despite being studied for a very long time, there is still no general description of the role of the various physicochemical parameters that affect the formation of these deposits. In this work, the formation of calcium carbonate scale deposits was computer simulated by calculating the interaction energy between calcite nanoparticles and real rough surfaces in calcium carbonate supersaturated solutions according to the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, using the surface element integration method. Quantitative scale deposition experiments were performed by the rotating cylinder technique while the influence of fluid dynamic parameters was investigated using microfluidic devices with different channel geometries. Results show that the effect of surface properties on the particle interaction depends on the physicochemical properties of the system and, therefore, a given surface may change its fouling behavior when the set of experimental conditions is changed..
Justyna Jońca Wrocław University of Science and Technology, Poland
Metal oxide nanocomposites prepared by localized hydrolysis of metal-organic precursors on WO3 nanoleaves and their applications for NO2 gas sensing and photocatalytic NO2 abatment
Over the past 20 years a simple, one-pot metal-organic procedure for the preparation of metal oxide nanoparticles has been developed at the Laboratoire de Chimie de Coordination. This method is based on the hydrolysis or oxidation of metal-organic precursors at room temperature and in controlled atmosphere in the presence of ligands [1-5]. Recently, a modification of this approach led to the formation of new nanocomposites where metal oxides nanoparticles were grown on WO3·2H2O nanoleaves . Thanks to the water molecules present in the crystal lattice of the WO3·2H2O, the hydrolysis of the metal-organic precursor was performed directly on the nanoleaves support without further addition of water and surfactants. Several nancomposite materials have been prepared following this protocol. Two of them, namely ZnO@WO3·H2O and Cu2O@WO3·H2O were characterized in details and used for respectively photocatalytic NO2 abatment and NO2 gas sensing [6,7].
The results revealed that, the ZnO@WO3·H2O nanocomposite after thermal treatment and additional 1% wt. gold nanoparticle decorating presents a remarkable increase (+166%) in the photocatalytic abatement of NO2 under UV as compared to the pristine WO3 nanoleaves. At the same time, the Cu2O@WO3·H2O nanocomposite has been deposited on the gas sensing device and after initial heating step up to 500oC used for NO2 sensing with greater sensitivity and selectivity toward this gas as compared to the pristine WO3 nanoleaves and CuO nanoparticles.
Yukihiro Tadokoro Toyota Research Institute of North America, United States
Efficient AI-Assisted Fabrication of Carbon Nanotube-Based Nanocantilevers for Advanced Sensing and Electromagnetic Applications
Nanoscale cantilevers (nanocantilevers) constructed from carbon nanotubes (CNTs) offer
substantial advantages in the realm of sensing and electromagnetic applications. However,
conventional fabrication techniques, such as chemical vapor deposition and dielectrophoresis,
are often laborious and time-consuming, involving manual processes like the placement of
additional electrodes and meticulous observation of single-grown CNTs.
In this study, we present an innovative, AI-assisted method for the efficient fabrication of
a large number of CNT-based nanocantilevers. Our approach leverages the power of deep
learning algorithms to identify randomly positioned single CNTs on a substrate, measure
their precise locations, and determine the optimal edge of the CNT for electrode clamping to
form a nanocantilever.
Our experimental results demonstrate that the AI -driven recognition and measurement
processes are completed in a mere 2 seconds, a significant reduction from the 12 hours
typically required for manual processing. Despite a minor measurement error by the trained
network (within 200 nm for 90% of the recognized CNTs), we successfully fabricated over
34 nanocantilevers in a single process. This high level of accuracy and efficiency contributes
to the development of a massive field emitter using the CNT-based nanocantilever, which can
generate output current at a low applied voltage. This capability opens up new possibilities
for the design and implementation of advanced sensing and electromagnetic devices.
We believe that our AI-assisted fabrication method represents a significant step forward in
the research and development of CNT-based nanocantilevers and holds great promise for a
wide range of future applications in sensing and electromagnetic technologies.
Surya R. Kalidindi Georgia Institute of Technology, United States
Accelerated development of materials using high-throughput strategies and AI/ML
The dramatic acceleration of the materials innovation cycles is contingent on the development
and implementation of high throughput strategies in both experimentation and physics-based
simulations, and their seamless integration using the emergent AI/ML (artificial
intelligence/machine learning) toolsets. This talk presents recent advances made in the
presenter’s research group, including: (i) a novel information gain-driven Bayesian ML
framework that identifies the next best step in materials innovation (i.e., the next experiment
and/or physics-based simulation to be performed) that maximizes the expected information
gain towards a specified target (e.g., optimized combination of material properties, refinement
of a material constitutive response), (ii) computationally efficient versatile microstructure
image analyses and statistical quantification tools, (iii) formulation of reduced-order processstructure-
property models that enable comprehensive inverse solutions needed in materials
design (e.g., identifying specific compositions and/or process histories that will produce a
desired combination of material properties), and (iv) high throughput experimental protocols
for multi-resolution (spatial resolutions in the range of 50 nm to 500 microns) mechanical
characterization of heterogeneous materials in small volumes (e.g., individual phase
constituents in multiphase material samples, thin coatings or layers in a multilayered sample). These recent advances will be illustrated with multiple case studies.
Ran Y. Suckeveriene Kinneret Academic College on the Sea of Galilee, Israel
Grafting of Polyaniline by a Dynamic Inverse Emulsion Polymerization Technique onto Membranes as an Anti-Biofouling Agent: An Innovative Approach
The demand for clean water is on the rise but since water sources are limited, the need for purification processes, such as membranes and filters, has become increasingly crucial. One of the main hurdles facing these processes is fouling and biofouling. In general, fouling is related to the deposition of macromolecules, colloids, particles and inorganic materials on the membrane surface and pores. Biofouling consists of the deposition of large bacterial colonies and biofilm on the membrane surface and inside the pores. Both are difficult to clean effectively. Anti-biofouling additives are typically insufficient, since they need to be stable to the water current and located at the surface of the membranes or filters. One of the suggested methods for effective biofouling prevention is the use of electrically conductive polymers (ICP).
This work describes an innovative approach for the anti-biofouling protection of membranes. This approach consists of a novel in-situ interfacial dynamic inverse emulsion polymerization process under sonication of aniline in the presence of carbon nanotubes (CNT) and graphene nanoparticles in organic solvent. The resulting hybrids were filtered, and the remaining filtration cake was used and analyzed as a nanocomposite membrane.
The resulting polyaniline (PANI) chains were grafted to the membrane surface, creating an anti-biofouling coating. High-resolution scanning electron microscopy (HRSEM) indicated that the nanocomposite membranes were coated with PANI. The grafted PANI exhibited a remarkably improved anti-biofouling effect. The membranes' salt rejection and flow properties were analyzed and showed that the flow properties were only slightly different compared to the reference membrane.
Brandon J. Teffta Medical College of Wisconsin & Marquette University, United States
Magnetic and biocompatible polyurethane nanofiber biomaterial for tissue engineering
Implantable cardiovascular devices such as vascular grafts, stents, stent-grafts, heart valves,
and flow diverters elicit adverse biological responses that may eventually result in device
failure. Establishing a living layer of endothelial cells on the blood contacting surface of these
devices would dramatically improve safety and efficacy. Our group has established
technologies to enable magnetic cell targeting for rapid and stable endothelialization of
implantable devices. Our latest advancement is the development of a magnetic and
biocompatible polyurethane nanofiber biomaterial that is suitable for tissue engineering
applications. We show this biomaterial has mechanical properties comparable to non-modified
polyurethane (ultimate tensile strength of 1.01 ± 0.64 MPa, stiffness of 0.66 ± 0.27 MPa, and
ultimate strain of 1.52 ± 0.24 mm/mm). We also show this biomaterial exhibits ferromagnetism
and is able to capture magnetically-labeled cells (6.83´103 ± 3.93´103 cells/cm2 for magnetic
group vs. 101.5 ± 57.7 cells/cm2 for control group, p<0.05). Captured cells remain viable for
at least 14 days in culture. Furthermore, we demonstrate this biomaterial can be used to
fabricate magnetic stent-grafts capable of crimping and expansion on a balloon catheter as well
as uniform capture of magnetically-labeled cells to the surface (22.2´103 ± 6.4´103 cells/cm2
for magnetic group vs. 7.4´103 ± 2.4´103 cells/cm2 for control group, p<0.05). This provides
proof-of-concept for a small-diameter stent-graft capable of rapid and stable endothelialization.
This magnetic and biocompatible polyurethane nanofiber biomaterial can be used to fabricate
a variety of implantable devices including vascular grafts, stent-grafts, and heart valves. The
magnetic properties allow for targeting of cells, drugs, and other beneficial therapeutic agents
to the device. This may improve outcomes for devices and engineered tissues within the cardiovascular system as well as other tissues and organs throughout the body.
Subhajit Dutta Sungkyunkwan University, South Korea
An Innovative Process to Achieve Stable Green and Red Emitting Phosphors for Cost-Effective Opto-electronic Applications
Rapid advancement in display technology has increased the demand for efficient visible light emitting phosphors. Till date, the oxide based phosphors has dominated the market. However, their processing complexities and oxide defects has pushed the research towards new phosphor materials. On this regards, manganese halide based materials has emerged as a suitable phosphor for display technology. Controlling the Mn-Mn bond length, the optical properties of these phosphors can be tuned from green to red [1,2]. Apart from that high defect tolerance of manganese halide phosphors open up a vast doorway for opto-electronic applications. Despite of such promising properties their synthesis complexity using toxic organic solvents pull the strings behind their success . To address this issues, here we present a simple water based synthesis method of Mn based phosphors. We have adapted lyophilization method for the synthesis of both green and red emitting Mn halide phosphors (Fig.1(a)). Being a greener option, our method presents an easy synthesis process. The X-ray diffraction peaks confirms the formation of the desired Mn halide phosphors (Fig. 1(b)). The bright green and red emissions from our synthesized Cs3MnBr5 and CsMnBr3 powders can be witnessed from photoluminescence emission (Fig. 1(c)). Matching the emissions of our phosphors in CIE color coordinate confirm their application for optoelectronic devices (Fig. 1(d)).
Jia Wang Shanxi Medical University, China
Utilizing nanozymes for combating COVID-19: advancements in diagnostics, treatments, and preventative measures
The emergence of human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses significant challenges to global public health. Despite the extensive efforts of researchers worldwide, there remains considerable opportunities for improvement in timely diagnosis, specific treatment, and effective vaccines for SARS-CoV-2. This is due, in part, to the large number of asymptomatic carriers, rapid virus mutations, inconsistent confinement policies, untimely diagnosis and limited clear treatment plans.
The emerging of nanozymes offers a promising approach for combating SARS-CoV-2 due to their stable physicochemical properties and high surface areas, which enable easier and multiple nano-bio interactions in vivo. Nanozymes inspire the development of sensitive and economic nanosensors for rapid detection, facilitate the development of specific medicines with minimal side effects for targeted therapy, trigger defensive mechanisms in the form of vaccines, and eliminate SARS-CoV-2 in the environment for prevention.
In this review, we briefly present the limitations of existing countermeasures against coronavirus disease 2019 (COVID-19). We then reviewed the applications of nanozyme-based platforms in the fields of diagnostics, therapeutics and the prevention in COVID-19. Finally, we propose opportunities and challenges for the further development of nanozyme-based platforms for COVID-19.
We expect that our review will provide valuable insights into the new emerging and re-emerging infectious pandemic from the perspective of nanozymes.
Kao-Shuo Chang National Cheng Kung University, Taiwan
Development of high-entropy high-dielectric-constant Ba(Ti,Zr,Ta,Hf,Mo)O3 film for metal−oxide−semiconductor field-effect transistors
The fabrication of high-entropy high-dielectric-constant (high-k) Ba(Ti,Zr,Ta,Hf,Mo)O3 film libraries on Si substrates through a high-throughput sputtering technique will be presented in this talk. Elemental variations and microstructures were characterized using high-throughput X-ray fluorescence (XRF) and X-ray diffraction, respectively. The film library was patterned into 100 metal−oxide−semiconductor (MOS) configurations to study their dielectric properties (e.g., k and loss) and equivalent-oxide-thickness (EOT). The library was also patterned into 35 metal−oxide−semiconductor field-effect transistors (MOSFETs) and subjected to rapid thermal annealing (RTA) to study their thermal stability. Herein, desirable performance was obtained, including an on/off current ratio, a saturated field-effect mobility, a threshold voltage, a subthreshold swing, and low interfacial defects. Furthermore, the resulting MOSFETs under various positive and negative gate-bias stress conditions before and after the RTA were also investigated. The results revealed that our devices outperformed various reported transistors, indicating the potential of the Ba(Ti,Zr,Ta,Hf,Mo)O3 films for use in a gate-first process for advanced gate stack-related devices.
Akamu Jude Ewunkem Winston Salem State University, United States
Honeybee wings (Apis mellifera): Green Synthesis and Antimicrobial Potential
Several natural surfaces have micro/nanostructures with extraordinary functionality namely self-cleaning and antimicrobial properties and green synthesis of nanomaterials. These properties are observed in the wings of insects such as cicadas, butterflies, termites, and dragon flies. However, wings of honeybee have received less attention. In the present study, we studied the surface-based nanostructure and bactericidal activity of the wings of honeybee to correlate the relationship between the observed surface topographical features and their bactericidal properties. Furthermore, these wings were utilized for green synthesis and cost-effective approach of silver nanoparticles. These nanoparticles were then characterized. These experiments revealed that honeybee wings were effective at inhibiting the growth of pathogenic microbes. Electron microscopy performed in this study showed that the antimicrobial activities were enhanced by an array of uniform pointed pillars distributed on both the dorsal and ventral sides of the wings. We also identified a chemical peak in the wings extract using HPLC suggesting the presence of bioactive chemicals. It was found that the synthesized silver nanoparticles were spherical, 40–60 nm in size and revealed strong absorption plasmon band around at 430 nm. Additionally, these nanoparticles exhibited a broad range of antimicrobial activities. The combined results presented not only correlates the nano structural organization to macroscale functional properties, but it also presents design guidelines to consider during the replication of natural surface onto engineered substrates to induce antimicrobial properties.
Luis Alfonso Garcia Cerda Research Centre of Applied Chemistry, Mexico
Magnetic polymer nanocomposites for controlled delivery of Doxorubicin anticancer drug and magnetic hyperthermia
Smart nanomaterials have been proposed to improve cancer treatments' efficacy by controlling antineoplastic drug delivery and selectivity in response to various stimuli such as temperature, pH, magnetic field, etc. Nanomaterials are attractive drug carriers because they transport hydrophobic and hydrophilic therapeutic molecules to the tumor site with minimal toxicity to surrounding tissues. Because of their nanometer-scale size, they can pass through the tumor vasculature and release the drug selectively. This work prepared thermo-responsive magnetic polymer nanocomposites for the controlled delivery of doxorubicin (DOX) anticancer drug. First, magnetite (Fe3O4) nanoparticles were synthesized by the inverse chemical co-precipitation method and functionalized with vinyltrimethoxysilane (VTMS). Then, free radical polymerization grafted poly (N-vinylcaprolactam) (PNVCL) onto the functionalized Fe3O4 nanoparticles. X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and transmission electron microscopy (TEM) were performed to characterize the nanocomposites. DOX molecules were loaded onto the nanocomposites, and the DOX release studies were carried out at 25 and 37 °C in a phosphate buffer solution (pH 7.4). According to the release studies, approximately 42% of DOX is released in 50 h, depending on the nanocomposite's polymer content. The magnetic polymer nanocomposites were also proven to be applicable in magnetic hyperthermia treatment; in concentrations of 8 mg/mL, they could heat up, increasing the temperature to 42 °C in a time lower than 10 minutes. They were also found to be highly hemobiocompatible in a hemolysis assay. The results indicate the high application potential of the magnetic polymer nanocomposites in combination with magnetic hyperthermia and controlled delivery of DOX.
Angelo Karunaratne University of Moratuwa, Sri Lanka
In situ 4D tomography image analysis framework to follow sintering within 3D-printed glass scaffolds
Additive manufacturing (AM) of glasses and ceramics usually requires the sintering of green bodies. Sintering causes shrinkage, which presents a challenge in controlling the metrology of the final architecture. Therefore, being able to monitor sintering in 3D over time (termed 4D) is important when developing new porous ceramics or glasses. Synchrotron X-ray tomographic imaging allows in situ, real-time capture of the sintering process at both micro and macro scales using a furnace rig, facilitating 4D quantitative analysis of the process. In this work, we propose a novel image analysis framework to automate the analysis of X-ray microtomography images of sintering ceramics and glasses using an open-source toolkit and machine learning. The proposed image analysis framework is capable of tracking and quantifying the densification of glass or ceramic particles within multiple volumes of interest (VOIs) along with structural changes over time using 4D image data. The framework is demonstrated by 4D quantitative analysis of bioactive glass ICIE16 within a 3D-printed scaffold. Here, the densification of glass particles within 3 VOIs were tracked and quantified along with diameter change of struts and inter-strut pore size over the 3D image series, delivering new insights on the sintering mechanism of ICIE16 bioactive glass particles in both micro and macro scales.
Friedrich Kremer University of Leipzig, Germany
The extraordinary mechanical properties of spider silk and its molecular foundation
Spider silk is a high-performance fiber with unique mechanical properties which are currently not met by man-made materials. It consists essentially out of two proteins, major ampullate spidroin1 and spidroin2, having alanine-rich blocks interrupted by glycine-rich sequences. The former assembles to -sheeted nanocrystals which are embedded in the amorphous chains of the latter and which are interlinked by a ~ 10 % fraction of prestressed chains. This causes within the fiber a negative inner pressure which is counterbalanced by the matrix surrounding the fibrils and by the outer skin. Wetting of the fiber results in a spontaneous “supercontraction” into the equilibrated state. - In the talk a detailed description of this interplay between inner and outer constraints will be discussed based on a variety of complementary experimental methods like polarized, time-resolved FTIR – spectroscopy, measurements of the mechanical modulus and micro-X-ray scattering. It enables one to deduce a quantitative model describing the macroscopic response in the dependence on the microscopic parameters.
Shuichiro Hirai Tokyo Institute of Technology, Japan
Nano-fiber technology for high-performance H2 / fuel cell system
Hydrogen / fuel-cell system is now considered to be a mayor energy system for countermeasure of global warming. Higher efficiency and low cost are needed for spreading the system. Hydrogen and air(oxygen) are supplied to fuel cell to produce electric power. Air is supplied to a reaction site through gas diffusion layer whose resistance of air transport is a major issue to improve efficiency. Gas diffusion layer is desirable to be thin as possible. In addition, it needs electric conductivity and gas permeability. We developed a new method to produce gas diffusion layer using nano-fiber. PAN is used as the raw material to produce nano fiber in a sheet of 0.05mm thickness. It is brought to a high temperature oven to raise the temperature up to 2300 K where PAN changes its molecular structure to have an electric conductivity. This new type of gas diffusion layer is tested in a fuel cell system to show a high performance compared to conventional one. Another aspect of gas diffusion layer is liquid water that is produced from oxygen and hydrogen accumulates inside the gas diffusion layer to block oxygen transport. Our team also have a special technology to measure liquid water inside gas diffusion layer under operation mode of fuel cell. Soft X ray is used for the visualization. In-situ liquid water measurements of the new gas diffusion layer and conventional one are compared. The new gas diffusion layer shows a drastic suppression of liquid water compared with that of conventional one which leads to high performance of fuel cell.
Jian Qiang Liu Jiujiang University, China
Enhanced electrochromic properties of WO3/ITO nanocomposite smart windows
Tungsten oxide is regarded as the most promising electrochromic materials due to its continuously tunable optical properties, low cost, and high coloration efficiency. The WO3 nanosheet is fabricated by acid-assisted hydrothermal process with high product efficiency. The introduction of ITO into WO3 nanosheets significantly improves the electrochemistry activity and the conductivity of composite film. Compared with reported electrochromic film without ITO doping, our synthesized composite WO3 film show optical modulation up to 88% and high coloration efficiency of 154.16 cm2/C. Particularly, our electrochromic film is based on the dispersant solution and coating technology, which can be realized with wire bar coating for large scale applications. The results offer an effective way to develop large-area and low-cost electrochromic film and devices.
Parameswaram Ganji National Institute of Chemistry Ljubljana, Slovenia
Nanomaterials for the conversion of carbohydrates to 5-hydroxymethylfurfural
Energy-efficient and sustainable processes for the production of 5-hydroxymethylfurfural (HMF) from carbohydrates are in high demand. HMF is referred to in the literature as a “sleeping giant” because it can be transformed into useful products, such as pharmaceuticals, fuels and polymers.
The nanocatalysts were synthesized using a microwave-assisted hydrothermal method, which is rapid, environmentally friendly, energy efficient, and an attractive choice for promoting reactions by dielectric heating. Moreover, microwave dielectric heating route enhances the yield and material purity and narrows the size distribution. Bivalent ion-exchanged microwave- synthesized ZnxTPA/γ-Al2O3 was employed for the direct conversion of carbohydrates to HMF. The as-synthesized samples were structurally characterized by FTIR and Raman spectroscopy, UV-Vis diffused reflectance spectroscopy and X-ray diffraction. Thermal characterization was performed using TG-DTA. The surface morphology was analyzed using FE-SEM, and surface area analysis was performed. The surface acidities of the as-synthesized catalysts were elucidated by pyridine FTIR spectra and NH3-TPD. The catalytic performance was thoroughly studied as a function of Zn2+ doping, reaction temperature, catalyst loading and solvent effect. The microwave-synthesized Zn0.5TPA/ γ-Al2O3 showed excellent catalytic dehydration of fructose with an HMF yield of 88% at 120 °C for 2 h. The catalytic performance of the Zn0.5TPA/ γ-Al2O3 was found to be excellent. It was found that the Brønsted acidity of the surface is crucial for optimal catalytic activity.
Marzia Cirri Univ. Florence, Italy
Design, Evaluation and Comparison of Nanostructured Lipid Carriers and Chitosan Nanoparticles as Carriers of Poorly Soluble Drugs to Develop Oral Liquid Formulations Suitable for Pediatric Use
Development of drug formulations tailored for pediatric use is one of the main challenges for the pharmaceutical industry and regulatory agencies, due to the growing needs for accessible age-appropriate pediatric medicines able to ensure a safe and effective adherence to the prescribed treatment. The lack of pediatric drug formulations often leads to extemporaneous preparations obtained from adult dosage forms, with consequent safety and quality risks. Among formulations, oral solutions represent the best choice for pediatric patients, due to administration ease and dosage-adaptability, but their development is challenging, particularly for poorly soluble drugs. Nanotechnology has become a key tool to overcome fundamental (bio)pharmaceutical drawbacks of drugs such as poor aqueous solubility, low physicochemical stability and insufficient bioavailability. The use of nanoparticles, particularly those based on natural polymers or lipid materials represent a promising and versatile approach for delivery of hydrophobic drugs, due to their safety, biocompatibility and biodegradability, and their ability to improve dissolution and permeation properties of drugs, thus enhancing their oral bioavailability. In this work, chitosan nanoparticles (CSNPs) and nanostructured lipid carriers (NLCs) were developed and evaluated as potential nanocarriers for preparing oral pediatric solutions of cefixime (poorly soluble model drug). The selected CSNPs and NLCs showed a size around 390 nm, Zeta-potential > 30 mV, and comparable entrapment efficiency (31–36%), but CSNPs had higher loading efficiency (5.2 vs. 1.4%). CSNPs maintained an almost unchanged size, homogeneity, and Zeta-potential during storage, while NLCs exhibited a marked progressive Zeta-potential decrease. Drug release from CSNPs formulations was poorly affected by gastric pH variations, differently from NLCs, and gave rise to a more reproducible and controlled profile. Also cytotoxicity studies confirmed CSNPs as the best nanocarrier, proving their complete biocompatibility.