CINBIO, Universidade de Vigo, Department of Physical Chemistry, Spain
Giuseppe Valerio Bianco
Vellore Institute of Technology, Chennai, India
Swiss Cluster AG, Switzerland
Chulalongkorn University, Thailand
Teklebrahan Gebrekrstos Weldemhret
Changwon National University, South Korea
Franken Maxit GmbH und Co. KG, Germany
Université Paris Cité, France
Noblegen Inc, Canada
National Institute for Materials Science, Japan
Jorge David López Gutiérrez
Toluca Institute of Technology, Mexico
Victor Hugo Mendez-Garcia
Autonomous University of San Luis Potosí, Mexico
Paul C. DeRose
National Institute of Standards and Technology (NIST), Gaithersburg, USA
Khalifa University, Abu Dhabi , United Arab Emirates
Khalifa University, United Arab Emirates
Helen M. Chan
Lehigh University, United States
Hassan I University - Settat, Morocco
Unidad de Biomedicina UCLM-CSIC, Spain
Ftema W. Aldbea
Sebha University, Libya
Jae Soo Yoo
Chung-Ang University, Korea
Mengmeng (Dawn) Xu
The University of Western Australia, Australia
Yamagata University, Japan
Space Environment Simulation Research Infrastructure, Harbin Institute of Technology, China
Jeong Ho Cho
Korea Institute of Ceramics Engineering and Technology, Korea
Haven Co., Ltd., South Korea
University of Castilla – La Mancha, Spain
Silvia Rincón Pérez
Industrial University of Santander, Colombia
National Kaohsiung University of Science and Technology, Taiwan
National Institute of Technology Raipur, India
Sayyeda Marziya Hasan
Shape Memory Medical Inc., USA
Prof. Vistasp M. Karbhari
University of Texas Arlington, United States
Politecnico di Milano, Italy
Elida de Obaldia
Universidad Tecnológica de Panamá, Panama
Replicor Inc., Canada
Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, China
Bruno Martins de Souza
Military Institute of Engineering, Brazil
Fetiye Esin Yakin
Sabanci University, Turkey
KTH Royal Institute of Technology, Sweden
Tania Guadalupe Peñaflor Galindo
National Institute of Technology, Nagaoka College, Japan
Tel Aviv University, Israel
Sabanci University, Turkey
School of Materials and Chemical Technology, Tokyo Institute of Technology, Japan
Anthony P. Marino
Texas A&M University, College Station, United States
National Autonomous University of Mexico, Mexico
Damaris Chieregato Vicentin
Federal University of Sao Carlos, Brazil
Erico Souza Teixeira
CESAR School, Brazil
The University of Texas at Arlington, United States
Hochschule Karlsruhe - University of Applied Sciences, Germany
ITMO University, Russia
Renaissance School of Medicine/Stony Brook University, United States
Polya M. Miladinova
University of Chemical Technology and Metallurgy, Bulgaria
Dimka Ivanova Fachikova
University of Chemical Tehnology and Metallurgy, Bulgaria
Sim Wan Annie Bligh
Caritas Institute of Higher Education, Hong Kong
Warsaw University of Technology, Poland
Fraunhofer IPMS, Germany
Novolipetsk Steel PJSC (NLMK), Russia
Delhi Pharmaceutical Sciences & Research University, India
University of California, United States
Ran Yosef Suckeveriene
KINNERET ACADEMIC COLLEGE on the sea of galilee, Israel
University of Araraquara, Brazil
Eunjung Ko Korea Institute for Advanced Study, South Korea
ferromagnetic Fe3GeTe2/CrGeTe3 moiré heterobilayer
Owing to unique fundamental physics and device applications, twisted moiré physics in two-dimensional (2D) van der Waals (vdW) layered magnetic materials has recently received particular attention. We investigate magnetic vdW Fe3GeTe2 (FGT)/CrGeTe3 (CGT) moiré heterobilayers with twist angles of 11o and 30o from first-principles. We show that the moiré heterobilayer is a ferromagnetic metal with an n-type CGT layer due to the dominant spin-majority electron transfer from the FGT layer to the CGT layer, regardless of various stacked structures. The spin-majority hybridized bands between Cr and Fe bands crossing the Fermi level are found regardless of stacking. The band alignment of the CGT layer depends on the effective potential difference at the interface. We show that an external electric field perpendicular to the in-plane direction modulates the interface dipole and band edges. Our study reveals a deeper understanding of the effects of stacking, spin alignment, spin transfer, and electrostatic gating on the 2D vdW magnetic metal/semiconductor heterostructure interface.
Radislav Potyrailo General Electric Research, Niskayuna, NY, USA
Industrial perspective on innovations in gas sensors: from one year's fundamental science to another year’s product
Reliable diagnostics of viral infections from breath, ambient air quality, industrial safety, homeland security – are some examples of unmet gas monitoring needs in unobtrusive formats because existing concepts of gas sensors reach their fundamental performance limits.
This plenary talk will stimulate your senses by (1) posing fundamental questions on principles of gas sensing and (2) showing earlier unthinkable sensor capabilities delivered by modern multidisciplinary research. We will discuss design principles of our multi-gas sensors that operate across the electromagnetic spectrum ranging from radio to optical frequencies.
In our radio-frequency sensors we introduced a dielectric excitation scheme of semiconducting metal oxide materials on the shoulder of their dielectric relaxation region. Our scheme provided unexpected boost in performance of these popular sensing materials over their chemiresistor readout . Our excitation scheme based on contemporary electronics brought highly desired features, e.g. linear sensor response, dynamic range of six decades of gas concentrations, and 50-fold improvement in the limit of detection versus chemiresistors. We lab-tested our excitation scheme with numerous gases, performed field validations on drones and in wearable formats and launched a commercial product with our partners.
In our photonic sensors, multi-gas selectivity is achieved within a single nanostructured sensing unit that produces a bright visible light iridescence [2-4]. By utilizing individual nanostructured sensors rather than sensor arrays we have improved sensor stability by eliminating independent aging factors in separate sensors in their arrays. Our existing and new machine learning (a.k.a. chemometrics) tools further advanced our sensor designs and performance in detection of multiple gases.
Toshio Fujimura JFE Techno-Research Corp., Japan
Analysis of the Solidus Temperature of Multicomponent Steel
Is the assumption of a constant solidus temperature—which has been empirically adopted in general steel solidification analysis without firm validation—valid in all solidification stages? This long-standing query has still remained owing to the difficulties in achieving the reliable measurements of the solidus temperature while the measurements of the liquidus temperature reasonably agree with phase diagrams.
To examine this assumption of a constant solidus temperature in all solidification stages for multicomponent steels, heat- and solute-transfer equations were simultaneously solved using the finite thickness model1), which focuses on early-to-late stage solidification except final stage solidification. In early-to-middle stage solidification, the model provides a constant solidus temperature, as predicted by the previously reported semi-infinite thickness model2),3) by the present authors wherein the solidification front was far from the strand center. In late stage solidification, however, the present model exhibited a slightly decreased solidus temperature—almost within the temperature measurement accuracy range. This suggests that the assumption of a constant solidus temperature does not exactly hold in late stage solidification, but is not unreasonable from a practical viewpoint. The obtained solutions agree well with numerical analyses and are in reasonable agreement with thermo-analytical measurements and industrial findings. Thus, the present model supports the assumption of a constant solidus temperature and estimates the solidus temperature in early-to-late stage solidification, which can play a role in search of an adequate solidus temperature as an approximate analytical solution for multicomponent steels.
Scott Keving Cushing California Institute of Technology, USA
Measuring photoexcited charge carrier energetics, transport, and strong electron-phonon coupling with ultrafast x-ray spectroscopy
Transient X-ray and extreme ultraviolet (XUV) spectroscopy use a core level transition to element specifically measure electron and hole energies as a function of time after photoexcitation. Using reflectivity geometries, few to hundreds of nanometer penetration depths can be achieved to isolate critical surface dynamics. Phonon modes and strong electron-phonon coupling, such as polarons, can be detected by their modulation of the X-ray edge structure. Combined, a complex picture of photoexcited carrier dynamics can be formed even in multi-material junctions. In this talk, we use transient X-ray spectroscopy to investigate a range of emergent phenomenon in applied materials. This includes a discussion of mid-gap states and band hybridization effects in ZnSe1-xTex alloys for CO2 reduction, attempts to remove excited state polaron formation in various iron oxide compounds, strong electron-phonon coupling in superatomic materials, and the advances in X-ray theory needed to understand these measurements.
Gustavo Valdati Miranda Universidade do Extremo Sul Catarinense, Brazil
Hydro deformation in ceramic tiles at the pre-firing stage
The production of ceramic tiles with larger sizes and reduced thickness has increased the challenge of producing high-quality ceramic tiles in short single-firing cycles. For porcelain tiles, the pressing step is of upmost importance for the microstructure of the green bodies. The particle size distribution, mineral composition of the pastes and porosity before firing define the water flow during the decoration process. Hydro deformation is the curvature of unfired ceramic tiles caused by water absorption during the decoration step before firing. In this work, the hydro deformation is studied in function of tile thickness, compaction, and clay composition according to a 2K factorial design. Two compositions of porcelain tiles (glazed and polished) were pressed at two thicknesses (3–6 mm) and pressing pressures (35.5–49.8 MPa) forming ceramic tiles with 55 × 110 mm2 of surface area. Chemical (XRF), mineralogical (XRD), thermogravimetric (TG), specific surface area (BET), granulometric, bulk density, and porosity analyses were performed for the green tiles of both compositions. To simulate the hydro deformation during the decoration step, the curvature (mm) of the tiles was studied within a 0–180 min interval. The water absorption rate through the surface (g.m−2⋅s− 1) of the tiles in an interval of 0–180 s was studied as a function of thickness, pressure and porcelain tile composition. As a result, the thickness of the tiles can change the curvatures from concave to convex. Pressing conditions and composition of the tiles can change the water absorption rates. Porcelain tiles with higher content of clay minerals develop convex curvatures. For tiles with lower content of clay minerals, concave curvatures were developed.
Gustavo Bodelon CINBIO, Universidade de Vigo, Department of Physical Chemistry, Spain
Development of bacterial biosensors based on surface-enhanced Raman scattering for multiplex detection
The progress in synthetic and computational biology has significantly improved our capability to fabricate robust bacterial biosensors. These and other advancements have made possible, for instance, the use of engineered E. coli as a programmable living tool for diagnostic and environmental applications. However, the dependency of bacterial biosensors on bioluminiscence, fluorescence, or colorimetric reporters severely limits their use for those applications requiring the simultaneous detection of multiple targets in the same sample. Surface-enhanced Raman scattering (SERS) spectroscopy is an analytical technique that employs plasmonic nanoparticles as optical enhancers for increasing the inherently weak intensity of the Raman signal. The main features of SERS include its high specificity, sensitivity, and multiplexing capabilities owing to the narrow spectral bandwidths that characterize the Raman spectra. In this work, we aim to develop bacterial biosensors with inducible expression of Raman-active molecules detectable by SERS. We expressed different Raman-active molecules in E. coli and implemented multivariate statistics, as well as machine learning tools, to investigate their potential use as reporters for multiplex detection. Our results demonstrate the suitability of the proposed approach. This study paves the way for a novel class of living biosensors based on SERS with improved capabilities for multiplex biodetection.
Giuseppe Valerio Bianco CNR-NANOTEC, Italy
Chemical Routes for Reaching Very Low Sheet Resistance Graphene
Graphene has been successfully applied as a promising candidate for substituting TCO in optoelectronic devices. Recent progresses in organic photovoltaic (OP) devices are highlighting the limits of the current transparent conductive oxide (TCO) technology. Metal ions diffusion from ITO, FTO and AZO layers has been identified as a common pathway for the degradation of organic photovoltaic devices. Graphene provides the advantages of chemical stability (also in the acid environment of an organic active layer) combined with the possibility of tuning its work function in order to optimize carriers collection as both anode and cathode.
In the laboratories of CNR NANOTEC, research is aimed at facing the main issues of a graphene technology: the improvement of the sheet resistance/transmittance figure of merit of graphene. In this contribution, we explore several chemical routes for the “heavy” p-doping of CVD graphene by both (i) surface chemical functionalization doping and (ii) substitutional doping methodologies. Our original doping strategies can provide multilayer CVD graphene with record conductive performances, which meet the technical target required by several industrial applications.
Atanu Dutta Vellore Institute of Technology, Chennai, India
Dual Mode Electrochemical Sensing of Trace Level NH3 for Exhaust Gas Application
Detection of ppm level ammonia in the exhaust gas as ammonia slip, while regenerating NOx catalyst, is mandatory to abide norm of emission. In the present work, we have developed electrochemical sensors based on ceria and lanthanum gallate electrolytes operating in both amperometric and potentiometric modes. Operating in the single chamber mode atmosphere this work studied and developed anode (active electrode) and cathode (inactive electrode) with preferential oxidation and reduction reactions respectively. While studying with Ni2+ doped CuO as anode and La0.5Sr0.5CoO3 as cathode the highest NH3 sensitivity of 225 A/decade and 116 mV/decade were obtained at 550C when anode was with 2 mol% Ni2+ doping in CuO and doped ceria electrolyte was with 15 mol% Gd doping (GDC15). On the other hand, while using La0.8Sr0.2Ga0.8Mg0.1Ni0.1O3 (LSGMN) electrolyte, exceptionally high sensitivity of 2124 A/decade and 338 mV/decade were observed at 550C. Electrical conductivity of Gd doped ceria and LSGMN electrolytes were studied in the temperature range 250-700C. Electrolyte conductivity as well as electrode-electrolyte interfaces played crucial role for sensing 3-40 ppm NH3, in addition to catalytic activity of the electrode materials at the operating temperature range 300-650C. Both the sensor structures were found fast in response and recovery. Stability of the performance of these sensors was found reliable. In presence of coexisting gases such as CO, NOx and HCs the sensors were tested for individual sensitivity along with ammonia sensitivity. Reasonably high selective sensing was found out for NH3 with respect to other gases. Impedance spectroscopy analysis and several other supporting experiments confirmed the sensing mechanism and reason why 2 mol% Ni2+ doped CuO produced highest sensing performance was also ascertained. Overall, the developed electrochemical sensors were found highly potential for exhaust gas monitoring.
Carlos Guerra Swiss Cluster AG, Switzerland
From sub-nanometer to micrometer films, or how to combine ALD with PVD
Thin-film deposition technologies are Key Enabling Technologies in the whole materials science domain in both academic research labs and industry. Specifically, physical vapour deposition (PVD) and atomic layer deposition (ALD) have shaped and progressed a significant number of research and industrial sectors.
These techniques have been growing independently in their own field, but when combined, they become an unparalleled materials factory. This combination offers endless variations of multinanolayered coating materials with superior properties and added functionalities.
In this presentation, I will show our work towards incorporating ALD to PVD from understanding how ALD films nucleate and grow on hydroxylated surfaces (i.e, Si-OH) and inert surfaces (i.e., carbon nanostructures, noble metals) to determine the physico-chemical properties of ALD films. One approach is to determine the geometrical arrangement of precursor molecules upon chemisorption (adsorbates) during pulsing, considering surface chemistry and the steric hindrance of the precursor at different temperatures. Secondly, monitoring the deposition of metal-oxides on non-functionalized singled-walled carbon nanotubes (SWCNTs) using in-situ Raman. The progression of adding precursor molecules in an ALD fashion allows to study the adsorption and chemisorption of the precursor molecules at different substrate temperatures. The gradual increase of the sp2-to-sp3 hybridization of carbon atoms revealed the progression in which nuclei grow from surface defects until film closure.
Along with other studies, this research work led to the development of the first cluster system combining ALD with PVD in a compact equipment, in order to synthesise complex multilayers composed of hundreds of nanolayers with high throughput. The properties and performance of such multinanolayered coatings are strongly influenced by the interfaces between the layers. Carefully engineered coatings translate to lighter and cheaper materials but with improved mechanical, electrical, and thermal properties. One such example is a 200 nanolayered metal-ceramic coating with improved hardness and yield strength.
TiO2/MXene-PVA/GO hydrogel-based electrochemical sensor for neurological disorder screening via norepinephrine detection in urine
Monitoring urinary norepinephrine (NE) levels is crucial for neurological disorder screening in clinical diagnosis. However, the conventional techniques used for norepinephrine detection still have some limitations, including complicated operation and expensive equipment. Herein, we present a novel hydrogel-based electrochemical sensor to sensitively monitor the NE level in urine. A titanium dioxide/MXene with polyvinyl alcohol/graphene oxide (TiO2/MXene-PVA/GO) composite was successfully prepared and applied to modify a screen-printed carbon electrode (SPCE) for urinary NE detection. The nanocomposite hydrogel structure of TiO2/MXene-PVA/GO was created and verified by scanning electron microscopy (SEM). Then, the as-prepared hydrogel substantially enhanced the sensor performance by electrocatalyst of TiO2, high surface area of MXene and sample pre-concentration on PVA/GO hydrogel. The electrochemical behavior of NE was investigated by cyclic voltammetry and amperometry. Under the optimal conditions, TiO2/MXene-PVA/GO hydrogel/SPCE response due to the oxidation of NE at +0.4 V (vs. Ag|AgCl) is proportional to the concentration of NE over 0.01 to 1.00 µM (R2 = 0.9968) and 1.00 to 60.0 µM (R2 = 0.9936) ranges with an associated detection limit (3σ) of 6 nM without interfering effect from the common interferences in urine. The method validation of the hydrogel-based electrochemical device with high performance liquid chromatography (HPLC) using a UV detector at 280 nm was also obtained. Ultimately, this device was sensitive enough to evaluate an early stage of neurological disorder via detecting clinically relevant NE in human urine, and it was able to be integrated with pantyliners as a wearable sensor.
Teklebrahan Gebrekrstos Weldemhret Changwon National University, South Korea
Ionic Liquid-Catalyzed Synthesis of Carbon/Polymer Nanocomposite Foam: Enhanced Flame-Retardant and Triboelectric Performances
Owing to their inherent ﬂexibility, compressibility, breathability, and convenient fabrication process, polyurethane foam (PUF)-based triboelectric nanogenerators (TENGs) are an excellent choice for the development of energy harvesting devices and self-powered sensors. However, most foams are victims of fire due to the extreme flammability of PUF. The addition of fillers during foam synthesis is proposed as a cost-effective means to overcome this problem. However, the addition of fillers significantly decreases the foamability and expansion ratio of the composite, thereby greatly affect the compressibility, flexibility, and density of the polymer/filler composite foam. Herein, an expandable graphite (EG)/carbon black (CB)/PU foam composite has been successfully fabricated using 1-butyl-3-methylimidazolium dibutylphosphate ([Bmim]DBP) ionic liquid as a catalyst. During polymerization, the [Bmim]DBP catalyzes the isocyanate/H2O reaction and generates CO2 gas in the form of bubbles. These bubbles act as a blowing agent and enhance the foamability and expansion of the carbon/polymer composite. Thus, the resultant EG/CB/PU sponge with high filler loadings (40 wt% on a basis of polyol) had low density and possessed excellent flexibility and compressibility. Besides, due to the presence of high carbon fillers, the resultant sponge exhibited excellent flame retardancy by preventing melt dripping after being ignited by a butane torch (≈1400 oC, applied for 20 s), self-extinguishing after torch removal, and reducing the peak heat release rate (a critical flammability metric) by 78%. A flame-retardant TENG (FR-TENG) was designed using the carbon/PUF composite. The FR-TENG could be attached to the insole of a shoe, generating an output of 36 V and 100 V by walking and running, respectively, sufficient to concomitantly glow 38 LEDs. This work offers a new perspective to develop flame-retardant and multifunctional carbon/polymer nanocomposites. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2018R1A6A1A03024509, 2022R1A2C2006081, and No. 2021R1I1A1A01057338).
Friedbert Scharfe Franken Maxit GmbH und Co. KG, Germany
Sprayable mineral Plaster insulation – A Mineral Composite Containing CSA Cement and Hollow Glass
In Germany 16% of the total greenhouse gas emissions originated from the building sector . The climate goals cannot be achieved with the current rate of energy refurbishment. A main key is the insulation of building however many of current insulation concepts are often problematic and have undesirable effects.
This contribution examines a plaster for insulating interior and exterior buildings. The so-called ecosphere system amortizes the costs. Ecosphere consists of calcium sulfoaluminate cement (CSA cement) and about a volume fraction of approximately 90% micro hollow glass beads (glass bubbles. CSA cement is an alternative cementitous binder which emits only 70% to 80% of the CO₂ compared with Ordinary Portland cement . Glass bubbles are thin walled (0.3-2.0 μm) spherical glass particles with a diameter of 30-200 μm (see fig. 1, left).
The processing technology is of crucial importance for the outstanding properties of the insulation. By improving existing spraying technologies for plasters it is now possible to apply this composite material to façades with a thickness of 15 cm without damaging the filigree glass bubbles. The compressed air-driven spraying process introduces additional porosity into the insulation, and thus further reduces thermal conductivity. Because of the high amount of porosity (93%), the glass bubble insulation has a density of just 125 kg/m3 and thermal conductivity of 0.040 W/mK. Moreover, because ecosphere is a purely mineral insulation material, it can be reused at the end of its life cycle as an aggregate for hydraulically binding building materials after crushing and moderate heat treatment.
Benoit PIRO Université Paris Cité, France
Printing technologies and printed electrolyte-gated transistors
Among many different kinds of electronic transducers for bioprobe-biotarget interactions, field-effect transistors (FETs) are among the most promising candidates. ISFETs were largely applied for monitoring biological events, e.g. pH changes produced by the activity of an enzyme. However, organic electrochemical transistors (OECTs) and electrolyte-gated organic field effect transistors (EGOFETs), transistors where the dielectric material is replaced by an aqueous solution and operating at voltages of a few hundreds of mV, opened the way for applications in water or even in or on living organisms. Just as examples, such transistors are able to transduce capacitive events occurring whether at the electrolyte/semiconductor interface or at the gate/electrolyte interface, such as antibody/antigen interactions or DNA aptamers/small organic molecules or proteins. We also demonstrated that a water-gated OFET is able to amplify the current coming from a microalgae’s photosynthetic activity placed on the gate electrode; a property that can be applied for monitoring the action of pesticides on living organisms. By the meantime, driven by the development of new functional inks, inkjet-printed electronics has reached several milestones, so that it is now possible to fabricate these transistors by mean of printing.
Shaojun Li Noblegen Inc, Canada
Modification and potential applications of Euglena base Polysaccharide
Euglena gracilis is a single-celled eukaryote which exhibits plant and animal characteristics. It is a model organism due to its robust growth in extreme environments, and production of valuable natural products, including the immune modulating paramylon. Paramylon has attracted considerable attention for its dietary qualities, various human health benefits, and utility in biodegradable packaging and materials. Structurally, paramylon is made up of B-1,3-glucan polymers arranged as intermolecular triple helices that form micro-glandular structures with high crystallinity. Functionally, paramylon and some of its derivatives are safe and effective coadjuvants, assist with insulin regulation, have antimicrobial, anti-cancer and wound healing properties, are potent antioxidants, UV protectant, and is a potential treatment for atopic dermatitis. Here we present an efficient paramylon isolation method from heterotrophically grown Euglena gracilis as well as preparation and characterization of paramylon derivatives through green methods. We have demonstrated the utility of paramylon and its derivatives as a pickering emulsifier, a replacement for the common whitening agent titanium dioxide, and the industrially relevant thickener, methylcellulose. We also demonstrated the potential applications of paramylon and its derivatives in food products as a fat replacement, and in cosmetic applications as a hydrogel and functional ingredient.
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.
Ran Yosef 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.
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.