National Institute for Environmental Studies, Japan
Md Salah Uddin
University of Texas Permian Basin, United States
CNRS University of Rouen UMR 6634 GPM laboratory, France
Interdisciplinary Science and Engineering Laboratory, University of Delaware, United States
National Autonomous University of Mexico, Mexico
The Catholic University of America, United States
Peking university third hospital, China
Luxembourg Institute of Science and Technology, Luxembourg
Joana A. Silva
IFIMUP, University of Porto, Portugal
Institute for microelectronics and microsystems (IMM) - CNR, Italy
Institute of Construction and Building Materials / TU Darmstadt, Germany
Hokkaido University, Japan
Dr Kajari Dutta
Amity University Kolkata, India
ITMO University, Russia
Korea Institute for Advanced Study, South Korea
Kumamoto University, Japan
Kent State University, United States
General Electric Research, Niskayuna, NY, USA
East China University of Science and Technology, China
National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute"', Ukraine
JFE Techno-Research Corp., Japan
The Pennsylvania State University, USA
Wrocław University of Science and Technology, Poland
Luis Felipe Paz Martinez
Universidad Politécnica de Madrid, Spain
Neslihan Tamsu Selli
Gebze Technical University, Turkey
Center for Physical Sciences and Technology, Lithuania
Scott Keving Cushing
California Institute of Technology, USA
Gustavo Valdati Miranda
Universidade do Extremo Sul Catarinense, Brazil
Coventry University, United Kingdom
IRAMIS/SPEC, Université Paris-Saclay, CEA, CNRS, France
IGM Resins c/o Insubrias Biopark, Italy
CINBIO, Universidade de Vigo, Department of Physical Chemistry, Spain
Giuseppe Valerio Bianco
Università di Milano-Bicocca, Italy
Vellore Institute of Technology, Chennai, India
CIRIMAT, Université Toulouse 3 Paul Sabatier, France
Institute of Electronics, National Yang Ming Chiao Tung University, Taiwan
Topchiev Institute of Petrochemical Synthesis, Russia
Naveed Ahmed Azam
Kyoto University, Japan
University of Miskolc, Hungary
Swiss Cluster AG, Switzerland
Chulalongkorn University, Thailand
1Department of Materials, University of Oxford, UK
Ana M.O. Azevedo University of Porto, Portugal
Protein discrimination using erythrosin B-based GUMBOS
In the past years, sensors have attracted increased attention as a facile and cost-effective approach for protein detection and discrimination. Different scaffolds have been employed for construction of sensors, including polymers, substituted porphyrins, and oligopeptide-functionalized resins 1. GUMBOS (Group of Uniform Materials Based on Organic Salts) have emerged as a promising class of materials for accurate identification of protein analytes. These compounds share similar features to those of ionic liquids, but have wide applicability potential due to their melting point range (25-250 ºC) 2. In this context, the usefulness of four novel erythrosin B (EB)-based GUMBOS as recognition elements for proteins with distinct molecular weights and isoelectric points was assessed. GUMBOS were synthesized using a simple metathesis reaction between the anionic dye (EB) and several phosphonium and ammonium cations. The effect of pH and incubation time on the discriminatory power was studied, being the assays performed in aqueous media at pH 3.0, 4.5, and 6.0 for 5, 10, and 15 minutes. Upon exposure to proteins, each sensor generated distinct absorbance response patterns that were analyzed using partial least squares discriminant analysis (PLSDA). The proposed sensing approach offers an interesting alternative to conventional analytical methods since it is simple (label-free) and rapid (only five minutes of equilibration time are required). Moreover, at pH = 6.0, EB-based GUMBOS allowed discrimination of five serum and non-serum proteins with 100% accuracy. The ability of GUMBOS to detect and discriminate between four distinct protein mixtures containing albumin and myoglobin was also studied. These binary mixtures were distinguished from each other with nearly 90% accuracy.
Jean Ebothe University of Reims Champagne Ardenne, France
Geometrical impact on Magnetic Properties of Mesoscopic Scale thick Nickel thin films
A real material thin film never exhibits a perfect or ideal geometrical shape, regardless of its
formation conditions. This is mainly depicted by its unavoidable bulk usually represented by
its thickness (d≠0) and its surface irregularities commonly considered in term of surface
roughness (σ≠0), both film characteristics being closely interconnected. Their individual
morphology and microstructure engender different behavior under a particular physical field
(E) effect. Any related film’s property (p) always results from their combined contributions.
The study of p evolution is commonly investigated through its dependence on d as mainly
encountered for macroscopic scale thick samples. However, configuration of real nano-films
and nanostructured thin films is specific most of the time. Consequently, the study of their p
evolution requires an adapted approach reflecting that specificity.
In the present work, our original proposal is illustrated by the study of nanostructured nickel
electrodeposits for which evolution of coercivity (Hc) and magnetic domain size (w) are
precisely investigated. It is then clearly demonstrated that only a new film geometrical
characteristic (τ) defined as τ = (d/σ) can consistently lead to the announced objective.
The study of these properties evolution using the normalization model indicates a
discontinuity in the magnetism of the investigated samples. Bloch magnetic domains (MD)B
are associated with mixed domain walls (DWN + DWB) below a critical position (τ0
-1) ≈ 0.35,
while Néel domain walls (DWN) coexist with mixed magnetic domains (MDB + MDN) beyond that position.
Emmanuel Péres de Araújo Military Institute of Engineering, Brazil
Laboratory scale production method of composite fuels for hybrid propulsion
Fuel formulation is one of the chief strategies in hybrid propulsion studies1. In this context,
polyethylenes-paraffins compositions have been suggested as a trade-off solution to attain
both mechanical quality and ballistic performance2,3. In parallel, mixed hybrids have proven
their capacity to enhance regression rates of thermoset polymers in mixture-modelled
experiments4. Ammonium perchlorate replacement by ammonium nitrate could turn mixed
hybrids into environmentally benign materials5. Meanwhile, the preparation of fuels based on
paraffins6,7 and thermoplastic polymers8 could benefit from an application-oriented approach,
capable to generate macroscopically homogeneous and symmetrical samples, compatible
with both instrumental and ballistic measurements. Therefore, a laboratory scale batch
method for the preparation of composite fuels for hybrid propulsion comprising low density
polyethylene (LDPE), paraffin and ammonium nitrate was successfully developed, yielding a
protocol consisting of two major steps, i.e., vigorous mixing at high temperature and natural
cooling centrifugal casting. This method allowed the repetitive production of single circular
port cylindrical grains (Figure), with a volumetric contraction in the 7% - 18% range, prone
to be used both in static firings and in instrumental analysis9. TGA and DSC results suggested
that the attained partial miscibility level between LDPE and paraffin, yielding a
crystallization enthalpy in the -320 J/g range, was enough to provide a good compositional
uniformity in the radial axis of the grains and a crystallization behavior compatible with the
inexistence of major cracks. Under the overall experimental conditions adopted, the
volumetric contraction of pure paraffin, i.e., 9.9%, was found to be lower than literature data,
as well as crystallization enthalpy results suggested a synergistic interaction between LDPE
and macrocrystalline paraffin, away from the additive rule9. The devised preparation method
and its macroscopic and microstructural findings are expected to be useful in hybrid
propulsion studies, regarding particularly the proper definition of novel LDPEmacrocrystalline
paraffin-NH4NO3 composite fuels’ formulations.
Soon-Gil Yoon Chungnam National University, South Korea
Unprecedented Flexibility of In-Situ Layer-by-Layer Stacked Graphene with Ultralow Sheet Resistance
Although graphene has been extensively studied as a candidate transparent conducting electrode (TCE) material for next-generation flexible devices, transferred large-scale graphene inevitably suffers from wrinkles, ripples, and metallic residues, which significantly lowers its quality by increasing its resistance and reducing its flexibility under tensile strain. As a result, many studies have looked to decrease the sheet resistance and increase the flexibility of graphene, but the complicated fabrication processes and high costs involved are barriers to commercialization. In the present study, 4-inch scale monolayered graphene and layer-by-layer stacked graphene that do not require a transfer process were designed to exhibit high flexibility and ultra-low sheet resistance. Three-layered stacked graphene film grown in situ on a polyethylene terephthalate substrate had an ultra-low sheet resistance of ~ 16 sq-1 at an optical transmittance of ~93% and superior flexibility for 104 cycles under a tensile strain of 5%. However, the plastic deformation of the PET substrate considerably reduced the flexibility of the monolayered graphene. In contrast, monolayered graphene on polydimethylsiloxane, which did not undergo plastic deformation, exhibited unprecedented flexibility at a static tensile strain of 15% (radius of curvature: 0.6 mm) and for 3104 bending cycles under a tensile strain of 11% (radius of curvature: 0.9 mm). This study provides an effective approach for the fabrication of TCEs for use in foldable electronic devices.
Kazuo Yamada National Institute for Environmental Studies, Japan
The outline and the background of “Recommendation of RILEM TC 258-AAA: RILEM AAR-13: application of alkali-wrapping for concrete prism testing to assess the expansion potential of alkali-silica reaction”
Various test methods and models have been developed to evaluate the alkali reactivity of aggregates and to estimate the long-term expansion behavior of concrete, and the test results have been compared with the behavior in the field. Since the expansion of ASR is caused by the formation of expansive reaction products of reactive silica in the aggregate and alkali in the pore fluid, the most essential points required for the test method are the alkali content and moisture content. Of course, apart from the properties of the aggregate itself, there are many other factors related to ASR expansion, such as water-to-cement ratio, mixing ratio of reactive and non-reactive aggregates, SCMs, aggregate size, temperature, age of the evaluation, humidity, etc., which result in different micro-textures of cracks, different reaction products, and different pore fluid compositions, and then resulting in different expansion dynamics and deformation characteristics of the structure. In order to investigate these factors and develop models to estimate the performance of structures, the most basic and important point is to first perform tests under controlled conditions of alkali content and moisture supply.
As an example of the influence of alkali leaching, which is considered to be one of the important influencing factors, the influence of specimen size will be explained: cylinders of Φ10 cm and blocks of 40 × 60 × 60 cm were made of the same concrete mixture and placed in different climatic locations in Japan. It was observed that the smaller cylinders showed less expansion. Analysis showed alkali leaching over several centimeters from the surface, which may have been the cause of the reduced expansion. When the same mixtures were tested in the laboratory with RILEM AAR-3 or 4, significant alkali leaching from the specimens and mass loss due to limited moisture supply were also detected.
A vast amount of data has been accumulated in ASR studies so far, but unfortunately, due to this circumstance explained above, it is questionable how reliable the data can be in terms of lab-field correlation. If the test method has a strictly defined procedure and reproducibility has been confirmed, any test method can be used, as long as the purpose of the test is limited to the determination of the harmlessness of aggregate or specific concrete in a certain area, since the criteria for determination are based on engineering experience. However, when trying to scientifically examine the influence of various factors, an appropriate test method is necessary. In order to realize the requirements of keeping the alkali content constant and supplying sufficient water, the authors proposed alkali-wrapping for concrete prism testing, currently published as RILEM AAR-13: application of alkali-wrapping for concrete prism testing to assess the expansion potential of alkali-silica reaction.
Md Salah Uddin University of Texas Permian Basin, United States
Molecular dynamics simulations and experimental characterization of chitosan hydrogel with different crosslinking agents for targeted drug delivery
Chitosan is a water-soluble, non-toxic, biodegradable, cationic, linear polysaccharide that is widely used in targeted drug delivery. In this study, two major cross-linkers Genipin and Disulfide have been selected to crosslink linear chains and investigate their effect on drug distribution with molecular dynamics simulations and loading/releasing rate with experimental characterization. Genipin is a small molecule, acts as a nontoxic linker, and can undergo self-polymerization whereas Disulfide crosslinking is a polymer-polymer crosslinking where the reaction takes place under neutral conditions and provide mucoadhesion. The cross-linking process is heavily impacted by the temperature and the pH conditions. To investigate the drug loading and releasing rate, Thymoquinone, Gefitinib, and Erlotinib have been selected for the linear chitosan along with two other cross-linked systems conducted in Phosphate buffer solution. This experiment guides to observing the drug loading and releasing efficiency of the linear chitosan and the cross-linked chitosans depending upon the amount of cross-linking used. The swelling ratio for the polymeric system is also observed and it is found to be improved with genipin and disulfide crosslinking. A previous study has been conducted to investigate the drug distributions with molecular dynamics simulations. Chitosan hydrogel network is constructed using three different crosslinking agents, soaked with water, and thermal cycles are applied to estimate the critical temperatures. Subsequently, three different drug molecules are incorporated into the models separately and the distributions are observed by analyzing the trajectories of the drug molecules obtained from the simulations performed with canonical ensembles, as the distributions will affect the drug discharge.
Allisson Saiter-Fourcin CNRS University of Rouen UMR 6634 GPM laboratory, France
What about new knowledges on the physical aging process?
Knowing the physical aging process is essential for predicting the time-dependent behavior of glass-forming liquids. The way by which a glass reaches (or not) its equilibrium state after a certain time is still matter of debate in the scientific community 1. Recently, it has been proven that this way is clearly dependent of the gap between the glass transition temperature Tg and the aging temperature Ta in different glass-forming liquids: polymeric systems 2, metallic glasses 3, and chalcogenide glasses 4. When Ta is close to Tg, the kinetics of the enthalpy of recovery occur in one step, whereas for Ta far from Tg, multiple steps can appear.
Recently, the use of the fast scanning calorimetry (FSC) has generated many studies 5-7 proving that the physical aging can accelerate the ability to crystallize by forming nuclei after reaching of the equilibrium state. This phenomenon known from a theoretical point of view is difficult to evidence experimentally because it appears after the complete structural relaxation, but we highlighted it through the study of a Selenium glass.
Deb Jaisi Interdisciplinary Science and Engineering Laboratory, University of Delaware, United States
A novel approach for enhancing solubility through structural substitution of ions of a slow-release fertilizer
Modern agriculture has arrived at the crossroad of conflicting problems of keeping up the supplant food production and yet protecting water quality. Slow and controlled release fertilizers are developed towards minimizing the usage of natural resources and maximizing plant uptake. Research efforts on developing next generations of nanofertilizers are aimed to control the rate of release of nutrients and track transfer and transformation in soils and waters. Specifically, two approaches of tuning nanofertilizer are being investigated: altering crystal chemistry via substitution of cations and anions in structural sites in apatite and amorphous calcium phosphate and changing their surface properties including size, shape, and surface morphology. The structural incorporations of soluble ions and carbonate are found to enhance phosphorus release kinetics. Crystal defects created from altering the structural reorganization of a unit cell are likely dominating factors. The changes made in surface properties have counteracting effects. Inability to limit the number of variables among products complicates discrimination of the role of each parameter. Nonetheless, the current success made in optimizing the properties has aided in tuning the temporal need of phosphorus for plants.
Joel Antunez-Garcia National Autonomous University of Mexico, Mexico
The effect of chemical composition on the properties of LTA zeolite: A theoretical study
Nowadays, zeolites' commercial, technological, and scientific importance is undeniable. In 2016, the global zeolite market was estimated at $USD 29.08 billion1, with a steady annual growth expected at 2.5%. Zeolites are crystalline and porous materials with a composition based on sodium, aluminum, and silicon. In the zeolites, pores are of nanometric dimension and are interconnected by channels; these characteristics grant to the zeolites a large surface area compared to their volume. Detergents, catalysts, and absorbents are those materials that concentrate more than 80% of commercial needs. Recent studies show that electrochemical performance, flexibility, and stability of zeolite-based Li–air batteries promise high efficency and flexibility compared to others currently on the market2. However, despite the large number of applications known today for zeolites, the correct distribution of the elements that compose them remains unclear. It makes it impossible to understand specific reaction mechanisms and predict unknown electronic properties. The electronic properties of LTA-type zeolites in their siliceous (see Fig. 1), aluminized, and ferric frameworks compositions, all of which were selected in their sodium ion-exchange form and under anhydrous conditions, were studied through DFT computations. In the case of an aluminized framework, it was found that the non-Löwensteinian configuration is energetically more favorable and has better electronic conductivity than the Löwensteinian framework. The two different ferric frameworks under consideration presented a distinct nature and higher acidity than aluminized ones. Furthermore, it was observed that the purely siliceous LTA framework showed an inversion in the Löwdin charge trace behavior, suggesting that it is associated with its hydrophobic nature.
Sepideh Akhbarifar The Catholic University of America, United States
Thermoelectric Properties of Lead Ruthenate Derevatives
The derivatives of lead ruthenate pyrochlores were investigated by varying the Pb/Ru ratio in lead ruthenate (Pb2Ru2O6.5). All ceramic compounds were synthesized by solid state synthesis and the thermoelectric properties were measured between 298 and 573 K. All compounds were isomorphic. Reducing the number of Pb2+ ions create more vacancies in the Pb2O′ sublattice and changes the properties of the already existing oxygen vacancies, which are occupied by Pb 6s2 electron lone pairs in pure lead ruthenate. Decreasing the concentration of Ru4+ affects electrical conductivity, which is mainly governed by the RuO6 backbone structure of ruthenate pyrochlore. The underlying scattering mechanisms of electrical (σ) and thermal conductivity (κ), the Seebeck coefficients (S) of all ceramics were analyzed in terms of carrier concentrations, using existing quantum physical models. All ceramics were p-type and showed metal-like electrical conductivity and glass-like thermal conductivity. Therefore, the same scattering mechanisms were seen for all pyrochlores. Electrical conductivity σ(T) and electronic thermal conductivity κe(T) were governed by ‘electron impurity scattering’. The 3-phonon resistive process (Umklapp scattering) controlled the lattice thermal conductivity κL(T), which supports the electron-impurity scattering mechanism. In all compounds, the Seebeck coefficients were inversely proportional to the carrier concentration.
Jia-Kuo Yu Peking university third hospital, China
Fabrication of 3D-Printed PEGDA-GelMA-CSMA Hydrogel Scaffolds for Promoting Chondrogenic Differentiation
The limited self-healing ability of cartilage necessitates the application of alternative tissue engineering strategies for repairing the damaged tissue and restoring its normal function. Compared to conventional tissue engineering strategies, three-dimensional (3D) printing offers a greater potential for developing tissue-engineered scaffolds. Herein, we prepared a novel photo-crosslinked printable cartilage ink comprising of polyethylene glycol diacrylate (PEGDA), gelatin methacryloyl (GelMA), and chondroitin sulfate methacrylate (CSMA). Unlike direct 3D (bio)printing methods, we used an alternative strategy called sacrificial templating mediated by 3D printed templates[1-4]. Briefly, we used the conventional Fused deposition modeling (FDM) to print a poly (lactic acid) (PLA) porous scaffold as a mold, followed by mixing gel precursors and pouring it into the mold, leaving the liquid level a little above those. After exposure to 405 nm blue light for 10 s and removal of pre-mold, high-resolution 3D-printed hydrogel scaffolds were obtained with uniform interconnected pores. FDM enables the rapid fabrication of highly interconnected pore geometries and channel sizes[5, 6]. Moreover, it is a cost-effective approach to print high-resolution constructs compared to other 3D (bio)printing techniques which are often overwhelmed by the viscosity, yield stress and shear thinning behavior of bio-ink. The 3D scaffolds possessed favorable compressive elastic modulus and degradation rate. In vitro experiments showed good adhesion, proliferation, and F-actin and chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on the scaffolds. When the CSMA concentration was increased, the compressive elastic modulus, GAG production, and expression of F-actin and cartilage-specific genes (COL2, ACAN, SOX9, PRG4) were significantly improved while the osteogenic marker genes of COL1 and ALP were decreased. The findings of the study indicate that the 3D-printed hydrogel scaffolds possessed not only adequate mechanical strength but also maintained a suitable 3D microenvironment for differentiation, proliferation, and extracellular matrix production of BMSCs.
Clement Mugemana Luxembourg Institute of Science and Technology, Luxembourg
Ionic Polydimethylsiloxane-Silica Nanocomposites: From Synthesis and Characterization to Self-Healing Property
Polydimethylsiloxane (PDMS) is the most widely explored and utilized polysiloxane, possessing an extremely low glass transition temperature, excellent thermal stability, high permeability, and good biocompatibility. As a liquid at room temperature, most applications require PDMS to be chemically crosslinked and / or combined with nanofillers to realize the requisite mechanical properties. While mechanical reinforcement of PDMS by nanofillers is well-known, the realization of consistently high levels of dispersion of nanofillers in a PDMS matrix remains a challenge. One strategy to control nanoparticle dispersion involves grafting ionic functional groups to the nanoparticle surface (thus creating so-called nanoparticle ionic materials, or NIMs1) and combining these charged nanoparticles with a polymer matrix containing functional groups with the opposite charge. Following such an approach, we describe ionic PDMS-silica nanocomposites from (cationic) ammonium-functionalized PDMS and (anionic) sulfonate-functionalized silica nanoparticles formulated with the aim of influencing the distribution and dispersion of the nanoparticles. The impact of the PDMS molecular weight, charge density and charge location on the distribution, dispersion of ionic silica nanoparticles and on the mechanical reinforcement of the resultant nanocomposites is explored. The potential for self-healing arising from reversible ionic interactions located at the interface between polymer matrix and highly dispersed silica nanoparticles is investigated by studying the impact of ionic nanoparticles loading and the PDMS molecular weight under different healing conditions, i.e., temperature and humidity.2 Finally, coarse-grained molecular dynamics simulations are carried out to calculate the lifetimes of temporary ionic crosslinks between the nanoparticles and the polymer matrix comprising these nanocomposites3.
Joana A. Silva IFIMUP, University of Porto, Portugal
Giant magnetostriction in magnetorheological elastomers
Magnetorheological elastomers (MREs) are composite materials, consisting of magnetic
particles embedded in a polymer matrix, whose magnetoelastic properties can be tuned by a
magnetic field. These materials can be applied as vibration attenuators and absorbers,
magnetic switches and valves. In this work we produced low concentration MREs composed
of PDMS (silicone rubber) with helicoidal particles of FeCo-2V. The main goal was to
achieve high strain and large elasticity.
The FeCo-2V alloy is a widely available inexpensive soft ferromagnet. To produce the
MREs, we used a commercial grade of this material, Hiperco 50 (Carpenter Technologies).
Four different volume fractions were used, between 0.6vol% and 3.4vol%. Additionally, the
MREs were produced in isotropic and anisotropic geometry.
Physical characterization was performed, showing that the MREs have ferromagnetic
behavior. The crystallography shows that the elastomer and the particles retain two
independent phases. Additionally, the anisotropic energy of the anisotropic MREs was
measured and it is shown to increase with the volume fraction. The elasticity moduli were
determined, and we show that, in isotropic MREs, the Young’s modulus is unchanged by the
external magnetic field (200 Oe) and small variations of volume fraction. However, in
anisotropic MREs, the Young’s modulus increases with the volume fraction, and it takes
larger values under a magnetic field intensity of 200 Oe. This shows that the magnetization
state of the MREs directly influences the mechanical elasticity. The magnetorheological
(MR) effect is reported in anisotropic MREs with low volume fraction. We show that the MR
effect reduces with increasing volume fraction. The magnetostriction of the MREs was
determined at 3.5k Oe, and giant magnetostriction values were obtained in MREs with
volume fraction as low as 1.2vol%. The results were compared to reported values and we
show that the magnetostriction of low concentration MREs is increased by more than 2-fold,
while reducing the volume fraction of magnetic particles.
Giuseppe Tranchida Institute for microelectronics and microsystems (IMM) - CNR, Italy
DIRECT SYNTHESIS AND CHARACTERIZATION OF MIL-101 (Fe) CRYSTALS ON CARBON-BASED SUBSTRATE
Metal–organic frameworks (MOFs) have recently received large attention in the field of
heterogeneous catalysis, gas storage, drug delivery, and fuel cells because of their versatility,
large surface area, well-ordered porous structure, and tunable organic linkers/metal clusters.
MOFs are hybrid inorganic-organic crystalline materials formed by metal ions coordinated
through specific functional groups, such as carboxylated groups, to rigid organic ligands in
order to form one-dimensional, two-dimensional or three-dimensional porous structures. MIL
is a subclass of MOFs formed by trivalent metal centers and carboxylate ligands. In this work
we focus on the development of synthetic strategies to grow and optimize the chemical and
structural properties of MIL-101(Fe) on a conductive carbon-based porous substrate, which is
usually adopted as gas diffusion layer in electrolyzers and fuel cells. Nanostructured MIL
crystals were directly grown on the carbon substrate in mild conditions from a solution of
FeCl3·6H2O and terephthalic acid in DMF. The deposition was conducted at 110°C,
atmospheric pressure and varying the reaction time from 2 to 22 hours. The influence of the
reaction time on growth and nucleation of the MOFs in terms of crystallinity, crystal size and
surface coverage has been investigated. Infrared Spectroscopy (FT-IR), Energy Dispersion Xray
(EDX) and scanning electron microscope (SEM) analyses were performed to study the
chemical, compositional and morphological properties. The crystallographic structure was
investigated by X-ray Diffraction (XRD). The electrochemical properties were tested by Cyclic
Voltammetry (CV) experiments. The good crystalline properties and the stability upon
electrochemical testing of the MOFs synthetized on carbon-based substrates make these
nanostructures a promising material for catalytic processes related to iron, such as for example,
oxygen reduction or electrochemical reduction of nitrogen, to produce ammonia at low
temperature and pressure.
Neven Ukrainczyk Institute of Construction and Building Materials / TU Darmstadt, Germany
Geopolymer materials: acid resistance measurements and modeling
Geopolymers are inorganic nanomaterials that provide a promising environmental friendly alternative to mineral binders, used to cement construction and building materials. Well deigned geopolymers exhibit excellent resistance to acid attacks, outperforming conventional cement-based materials. This can be explained by geopolymers zeolite-like amorphous molecular structure that exhibits lower solubility than calcium-rich cementitious hydration products. Degradation of concrete structures by acid attack is of great interest in numerous applications, such as biogas, biowaste, power plant cooling tower, sewer and wastewater treatment plants.
This keynote lecture comparatively reviews the findings of our publications as well as presents experimental results analysed in a new manner, which enabled to perform novel calibrations of our mathematical modeling approach. The lecture makes comparative overview on a progress made concerning geopolymers binders leaching and acetic acid attack degradation mechanisms. Results are compared from a broader perspective to a parallel research that revealed geopolymers acid attack mechanisms when exposed to sulfuric acid in lab and biogenic field conditions. Most importantly, this synthesis enabled to further evaluate the diffusion-based models for alkali leaching from geopolymers on additional measurement results related to both sulfuric and acetic acid scenarios.
Under sulfuric acid case, precipitation of expansive sulfate salts further accelerates the damage process by cracking. Existing experimental methods for leaching in pure water were proposed for more aggressive conditions in acidic solutions. Tests under laboratory conditions combined analyses of both liquid and solid samples. In the exposure solutions, the eluted elements were measured over time by inductively coupled plasma (ICP) mass spectroscopy (MS) or optical emission spectroscopy (OES) and from elemental distributions at different depths determined on cross-sections of solid samples using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS)
Bunsho Ohtani Hokkaido University, Japan
Design, preparation and characterization of functional nanomaterials based on energy-resolved distribution of electron traps
How can we design functional solid materials, such as catalysts and photocatalysts? What is the decisive structural parameters controlling their activities, performance or properties? What is obtained as structural properties by popular conventional analytical methods, such as X-ray diffraction (XRD) or nitrogen-adsorption measurement, is limited to bulk crystalline structure and specific surface area, i.e., no structural characterization on amorphous phases, if present, and surface structure has been made so far. This is because there have been no macroscopic analytical methods to give surface structural information including possibly-present amorphous phases. Recently, we have developed reversed double-beam photoacoustic spectroscopy (RDB-PAS) which enables measure energy-resolved distribution of electron traps (ERDT) for semiconducting materials such as metal oxides [1,2]. Those detected electron traps (ETs) seem to be predominantly located on the surface for almost all the metal oxide particles, and therefore they reflect macroscopic surface structure, including amorphous phases, in ERDT patterns. Using an ERDT pattern with the data of CB bottom position (CBB), i.e., ERDT/CBB pattern, it has been shown that metal oxide powders, and the other semiconducting materials such as carbon nitride, can be identified without using the other analytical data such as XRD patterns or specific surface area, and similarity/differentness of a pair of metal-oxide samples is quantitatively evaluated as degree of coincidence of ERDT/CBB patterns. An approach of material design based on the ERDT/CBB analyses is introduced .
 Chem. Commun. 2016, 52, 12096-12099.  Electrochim. Acta 2018, 264, 83-90.  Catal. Today 2019, 321-322, 2-8.
Dr Kajari Dutta Amity University Kolkata, India
Room temperature synthesis of GO/Ag2O nanocomposite: Broad spectral ranged solar photocatalyst and high efficacy antibiotic for waste water treatment
With the worldwide industrial growth, major concern is rapid surge in water pollution. Notably, the water is contaminated by strong industrial dyes and pathogenic microorganisms. To address the issue, a simple heterostructure GO/Ag2O was synthesized in room temperature, which can serve the purpose of industrial waste management. In general, Ag2O nanostructures with absorptivity in NIR range is able to absorb 57% of solar spectrum, but our synthesized Ag2O nanowires can absorb Visible-NIR spectral range (peak ~ 850 nm) due to presence of multiple energy states, confirmed by the density of states (DOS) of Ag2O using density functional theory (DFT) analysis. Developing a nanocomposite with graphene oxide exhibited blue shifting of absorption maximum at 700 nm and improved absorptivity covering the entire solar spectrum (200-1800 nm). The DFT analysis of designed geometrical relaxed structure of GO/Ag2O approved the unique optical properties of nanocomposite. The nanocomposite degraded a very strong medical dye (Safranin-O) for 40 minutes white light exposures. In addition, our nanocomposite also showed antibacterial activity against E. coli with an MBC ~ 0.01 mg/ml. Molecular Docking analysis also established the improved interaction of an E.coli ribosomal and membrane protein with GO in nanocomposite in comparison with that of pure GO, which supports the experimental results. Fast charge transfer between Ag2O and GO increases the super oxide and hydroxide radicals in our synthesized hetero-system, which results excellent solar photocatalytic activity and ROS species to destroy the bacterial colonies.
Sadykov Dinislam ITMO University, Russia
Influence of low temperature on mechanical properties of UFG Al-Cu-Zr alloy
Ultrafine-grained (UFG) aluminum alloys are promising functional materials for use in various industries. However, for practical application, it is necessary to understand the influence of temperature regimes on their physical and mechanical characteristics. Recently  it was shown that additional alloying of HPT-processed Al-Zr by Cu leads to a dramatic increase in strength at room temperature while maintaining high level of conductivity. It has been shown that such enhancement of strength is associated with grain refinement and formation of nanoprecipitates of Al2Cu phase at grain boundaries during HPT processing. In this report, we studied the influence of low temperature in a range of 77–300 K on mechanical behavior of HPT processed Al-1.47Cu-0.34Zr (wt. %) alloy in comparison with such behavior of similarly structured UFG commercially pure (CP) Al and Al-0.4Zr (wt. %) alloy.
It is shown that yield stress and ultimate tensile strength increases with decreasing temperature for all three materials, however the rate of change of σ0.2 with decreasing temperature is nearly the same for all three material in the range 77–223 K and lower than in the range 223–293 K. The mechanical behavior of ultrafine-grained CP Al and Al-0.4Zr alloy are very similar in the whole temperature range 77-300 К. Alloying with Cu leads to substantial increase in the rate of the enhancement of σ0.2 with decreasing temperature in the range 223–293 K.
Accelerated strengthening with decreasing temperature in the range 223–293 K and influence of Cu on such strengthening is explained by using the concept of nonequilibrium grain boundaries in the UFG state and their influence on the emission of dislocations from grain boundaries, as well as considering the presence of Al2Cu precipitates at grain boundaries in the Al-Cu-Zr alloy.
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.
Taiga Yamasaki Kumamoto University, Japan
Bayesian spectroscopy of synthesized X-ray magnetic circular dichroism spectra at the Ni-L3, -L2 edges
X-ray magnetic circular dichroism (XMCD)1) measurement is an effective way to extract information about microscopic spin states of magnetic materials. Conventionally, the XMCD measurements at the L3 and L2 edges of magnetic elements have been performed to evaluate the spin and orbital magnetic moments based on the sum rule2). On the other hand, we applied Bayesian spectroscopy3) (BS), which allows us to trace back the causality by using Bayesian theorem4), to the analysis of the XMCD spectra. As a result, we succeeded in extracting spin state splitting for the respective helicities from the XMCD spectrum only and reconstructing the original −/+helicity X-ray absorption (XA) spectra5).
In this contribution, we also discuss the noise tolerance of BS on synthesized XMCD spectra prepared by mimicking the Ni-L3 and -L2 edges in NiFe2O46). Gray spectra in the Figure are the original −/+helicity XA spectra, and the superimposed noise in the right panels is two-times intense compared to the left panels. The analyzed XMCD spectra are the difference spectra between those −/+helicity XA spectra.
In BS on the XMCD spectra, the number of spectral components in each of the original −/+helicity XA spectra can be estimated by using Bayes free energy3) as the information criterion. Dashed curves represent decomposed components from XMCD spectra, and blue and red curves are their sum spectra. As seen both panels with different noise intensities, the reconstructed curves from the XMCD spectra well reproduce the original −/+helicity XA spectra. This result demonstrates that the BS for XMCD has high tolerance for noise.
Rabindra Dubadi Kent State University, United States
mechanochemical incorporation of metal oxide species on γ−alumina
Mechanochemistry has been used for the synthesis of γ-alumina with incorporated metal oxide (MO) species (M=Fe, Cu, & Zn). This synthetic route affords porous alumina with MO species having a large amount of interfacial defects on the alumina surface1. Various metal percentages (5, 10) were used to tune the composition of the resulting hybrid materials2. Boehmite used as alumina precursor and Pluronic P123 as a pore generating agent were grinded with suitable metal salts. The synthesized samples were calcined in air at 600 °C for 4 hours with a heating rate of 1°C/min because the γ phase of alumina is formed at 450-750 °C3. Commercial γ−alumina (SBET = 96 m2/g, VT = 0.54 cm3/g), and boehmite (SBET = 282 m2/g, VT = 0.34 cm3/g) were used as reference samples. γ-Alumina obtained after 3 hours of one-pot milling showed higher SBET 320 m2/g and VT 1.21 cm3/g. The synthesized samples were characterized by TGA/DTG, SEM, XRF, and N2 adsorption techniques. The intensity of XRF peaks increases with increasing dopant concentration showing an effective incorporation of MOs into alumina. Similarly, the synthesized sample with 5% metal content was tested for selective catalytic reduction (SCR) of NOx3,4. The highest NOx conversion rate (70%) was observed for the Fe modified sample at 450 °C and (71 %) for the Cu modified sample at 300 °C. For all MO modified samples, the N2O production did not exceed 20 ppm at the given temperature window, while the unmodified alumina showed the highest N2O production, indicating better catalytic performance of MO modified samples. This study shows that one-pot ball milling of boehmite along with P123 and metal salts affords porous γ−alumina with large surface area and high pore volume. The MO incorporated samples show higher efficiency for the NOx conversion without producing harmful N2O as a byproduct.
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.
Wei-Hong Zhu East China University of Science and Technology, China
Sterically Hindered Diarylethenes with Benzobis(thiadizole) Bridge: Enantiospecific Transformation and Reversible Photo-Superstructures
Photochromic diarylethenes feature the reversible regulation by external photo irradiation which have attracted increasing attentions due to the bistability and outstanding fatigue resistance. To date, most studies focus on side aryl groups instead of central ethene bridge. However, the aromaticity and steric hindrance of ethene bridge can greatly affect the photochromic performance of diarylethene on bistability, quantum yields and chirality. In the presentation, we introduce our unique sterically hindered diarylethene system as a star photochromic or photoresponsive building block with excellent bistability, high photocyclization quantum yields and enantiospecific transformation, which provides a widely potential application in non-destructive information encoding, self-assembled systems, liquid crystal modulation and so on.
Tetiana Roik National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute"', Ukraine
Self-lubricating mechanism of new copper-based composite
The article analyzes the tribological properties of a new composite antifriction material based on copper, alloyed with nickel, aluminum and silicon, with the addition of calcium fluoride (CaF2) solid lubricant. In this work, the structure and its effect on antifriction properties were studied during tribological tests under friction conditions at loads of 1.0–3.0 MPa and a rotation speed of 1200–2000 rpm in air. The effect of manufacturing technology on the formation of the copper-based composite structure has been studied. The contribution of nickel, aluminum and silicon alloying elements to phase formation in the material structure has been analyzed. Research focuses on the calcium fluoride distribution in a composite with a copper matrix, its role in the self-lubricating process of the material, the distribution of the friction pair’s chemical elements and solid lubricant CaF2 in the contact zone under severe operating conditions. It was shown the solid lubricant is evenly distributed over the contact surfaces, and it covers the entire friction area. It has been established that anti-seize films formed in the presence of CaF2 solid lubricant provide high wear resistance. Solid lubricant CaF2 promotes the antifriction films formation during the friction process and provides a self-lubricating mode for the high-speed friction unit. Such films defend the contact surfaces against the intensive wear and stabilize a work of the friction unit. Studies have illustrated the developed antifriction copper-based composite is 5-6 times more wear resistant than the well-known composite operating under similar conditions. The developed composite can be recommended for use in friction units of high-speed equipment, electric motors, and speed reducers.
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.
Chetan Nikhare The Pennsylvania State University, USA
Reduction of Young’s modulus and effect on springback
Sudden increase of fuel consumption and resulting air pollution is due to the higher usage of automotive vehicles. To control the pollution and its impact on the environment, the National Highway Transportation Safety Administration (NHTSA) and Environmental Protection Agency (EPA) issued new rules called the Safer Affordable Fuel-Efficient (SAFE) vehicles which sets stricter standards for fuel economy and carbon dioxide . The new set values for miles per gallon as per the SAFE for model year 2021 to 2026 are 44.6 to 54.6 . But even the bestselling car is not able to reach the target of year 2021 . Thus, the automotive industry is facing an ongoing challenge to reduce the vehicle weight to reduce the fuel usage per mile and to avoid the environmental regulation penalty. Therefore, the innovation related to light-weighting became a mandatory necessity. To reach this target, the industry has been looking option to manufacture parts from high strength to ultra-high strength steels. With the usage of advanced high strength steels, the lightweight was achieved by reducing the thickness of the material without compromising on strength. However, due to their high strength property often challenges occurred are higher machine tonnage requirement, sudden fracture, geometric defect, etc. The geometric defect comes from recovery of the original geometry due to material elasticity. This defect is called as springback. Springback is commonly known as a manufacturing defect due to the geometric error in the part. Due to this error the deviated part would not be able to fit in the assembly without opt-in for secondary operations. Traditionally, it was believed that the elasticity remains constant at any plastic strain. However, during testing advanced high strength steels it was found that the elastic recovery increases during loading and unloading with increase in plastic strain.
Agnieszka Cizman Wrocław University of Science and Technology, Poland
New insight into physical properties of multifunctional porous glass-based nanocomposites
A possibility of a material fabrication in the nanometer scale rendered new opportunities both for industry as well as in research. The industry pressure for high requirements of physical, chemical and mechanical properties and dimensions of new materials is doubtlessly the main reason of miniaturization. Searching for nano-materials with interesting properties for technical applications requires a mastering of their fabrication and a wide range of characterization and measurement methods. Materials science has become an unusually interesting research field these days due to extraordinary novel materials, more and more advanced fabrication and uncommon challenges. In this presentation the alternative method to obtained multifunctional materials will be discussed. The investigation of electrical, magnetic and thermal properties of porous glass-based nanocomposites allowed to described the fundamental knowledge in physics of ferroelectrics and ferromagnetic materials in nanoscale. The measurements of the surface structure and pores filling factor allows to determine the basic materials parameters for both the porous glasses and for the obtained nanocomposites. The interaction between the matrix and the embedded ferroics material, as well as about the influence of this interaction on the size effect will be discussed. Obtained results provide the new information about the structure and properties of the manufactured novel composites. So far there is no full theoretical description of the size effect of porous glass-based nanocomposites with the irregular pore distribution. Presented studies render a new insight into explaining the size effect of ferroics materials based on porous matrices.
Luis Felipe Paz Martinez Universidad Politécnica de Madrid, Spain
Dye doped waveguides emitters covering the visible spectrum
Polymer based photonic devices offer the possibility cost effective roll-to-roll manufacture of photonic devices. The light confining into optical micro structured organic waveguides opens the door to plenty of interesting applications in fields as biosensing, communications, optical computing, and optoelectronics. Moreover, its organic-based structures allow the easy incorporation of fluorescent materials within a solid polymer waveguide for the generation of light within the device avoiding tedious mechanical light coupling. However, when a dopant is embedded in a solid matrix, depending on its concentration and the nature of materials involved, the emitted light may be quenched due to aggregation effects. In this work, thin films and ridge waveguides processed by UV-photolithography have been successfully obtained from a selection of standard photopolymerizable organic monomers, SU8, EpoCore and OrmoStamp doped with a selection of standard dyes like Rhodamine-B (RhB), Coumarin-540A (C540A) and Pyrromethene-580 (Py-580). An analysis of the solubility and optical properties including band gap energy, absorption coefficient (α) and fluorescence of the doped photoresists at different concentrations has been performed. Fabrication protocols of dye doped photoresists covering the entire visible spectrum is established.
The use of halloysite nanotubes in traditional glazes: Investigation of the effect on optical and mechanical properties
The wear resistance of glazes is significant in traditional glossy wall tile glazes. It is expected that the glazes will both maintain their current shine and not be eroded simultaneously. In this study, halloysite nanotubes (HNPs) were added to the existing standard wall tile glazes to increase the abrasion resistance of traditional wall tile glazes. Halloysite nanotubes (HNPs) were obtained due to calcination of halloysite clay calcined at 600°C. The classic glossy glaze was doped at 0.1, 0.3, 0.6, 1.0, and 2.0 wt%. The doped samples' detailed technological, mechanical, heating microscopes, and microstructural characterizations were made. As the halloysite nanotube ratios increased, the hardness, surface wear values , and fracture toughness values of the glaze increased. The addition of HNPs at the maximum rate (2% by weight) provided the highest mechanical properties without changing the optical properties of the existing glaze.
Vitalij Fiodorov Center for Physical Sciences and Technology, Lithuania
Laser-assisted selective fabrication of copper traces on polymers by electroplating
Selective deposition of metals on dielectric materials is widely used in the electronic industry, making electro-conductive connections between circuit elements. We report a new low-cost laser-assisted method for selective deposition of copper tracks on polymer surfaces by electroplating. The method allows a production of copper tracks on complex shape materials where conventional methods are not suitable. The technology could be used in production of molded interconnect devices (MID), where the main technological problem and achievable task is the low-cost fabrication of copper tracks.
Our laser-assisted technology consists of two main steps: firstly, the electric circuit is laser-written on a dielectric surface. The electrical conductivity of some polymers could be increased due to laser irradiation. Then, the sample is immersed into the electrolytic solution, where laser-treated areas are copper-deposited. Polyimide (PI) Kapton® film was used in our experiments. Samples were treated using nanosecond and picosecond lasers working at 532 nm and 1064 nm wavelengths. The experiments were performed using pulse energies up to 115 μJ, pulse repetition rates from 100 to 400 kHz and a constant scanning speed of 100 mm/s. The sheet resistance was measured using the four-probe method, and it was reduced to < 10 Ω per square after the laser treatment. Several different modifications of PI surface regimes were found after treatment with different irradiation doses. Soot was formed on the surface of the sample when treating with irradiation doses from 17.75 J/cm2 to 130 J/cm2. A graphene-like layer was formed when the sample was treated with the irradiation doses of 4.42 J/cm2 to 10.76 J/cm2. Analysis of Raman spectra of specimens treated areas was performed. Finally, the copper layer thickness of 5-20 μm was deposited on the laser modified surface by electroplating.
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.
Latha Krishnan Coventry University, United Kingdom
Impact of Wet Chemical Pre-treatments in the Electroless Copper Coating of Natural and Synthetic Textile Materials
This work was carried out as part of the European Union funded MATUROLIFE project. Aimed to produce high value-added aesthetically pleasing and functional Assistive Technology (AT) products for older people to live more independently. A key enabling technology for these AT concepts is the incorporation of ‘smart textiles’ where electronic circuitry becomes part of the material itself. In this study an electroless copper coating process for textiles has been developed to produce smart textiles which involves multistep processes, 1) pre-treatment, 2) surface activation through catalysation and 3) electroless copper (Cu) plating. Among these three processes, the pre-treatment is the first and arguably the most important process that modifies the textile surface to uniformly absorb catalyst. In this way, the pre-treatment has a significant impact on the quality of the subsequent electroless Cu coating and physical properties. The aim of this research work is to investigate the effect of different wet chemical pre-treatments in electroless copper coating of natural (cotton) and synthetic (polyester) textile materials. In this study, seven different pre-treatment conditions were used. After the pre-treatment process, the textile surface was activated by palladium catalyst and then electroless copper coated. After electroless Cu coating, the extent of Cu coverage on metallised textiles was characterised by scanning electron microscope (SEM) imaging and energy dispersive spectroscopy (EDS) microanalysis. The rate of copper deposition was calculated from the weight gain of copper. Conductivity of the metallised textiles was measured using a four-point probe and adhesion of the Cu layer to the textile by tape test. The wettability of the pre-treated fabrics was measured using water contact angle measurements. It was found that the pre-treatment of the textile had a major influence on the deposition rate and has an effect on uniform coverage of Cu as shown by SEM, and weight gain.
Antoine BARBIER IRAMIS/SPEC, Université Paris-Saclay, CEA, CNRS, France
Properties of self-oxidized single crystalline perovskite N : BaTiO3 oxynitride epitaxial thin films
Novel and multifunctional materials are required to reduce carbon emissions in order to mitigate the effects of climate change as well as to reduce electronic device consumption and overall materials usage. Oxides offer a very wide range of physical properties allowing for a multitude of applications, they can exhibit a variety long-range magnetic or electric orderings as well as multiferroic behaviors and many have the required chemical stability for photocatalytic applications such as solar water splitting or CO2 reduction. Unfortunately, they have often non-ideal optical and electrical properties: either they mainly absorb UV light or their charge carrier recombination rate is penalizing. The insertion of nitrogen, less electronegative than oxygen, into the lattice of an oxide causes an increase in the covalent nature of the chemical bonds and thus a modification of the absorption properties and charge carriers concentration. Unfortunately, in nature, oxidation is largely more favourable than nitriding and the realization of oxynitrides is generally difficult. Realizing epitaxial thin films is even more difficult.
We realized epitaxial layers of N-doped BaTiO3, by molecular beam epitaxy, using an original approach consisting in using the SrTiO3(001) substrate as the oxygen supplier and atomic nitrogen plasma to incorporate substitutional N atoms into the perovskite lattice. The N source allowed also to extract ions during the growth. The layers were characterized by in situ high energy electron diffraction and Auger analysis, synchrotron radiation X-ray diffraction and photoemission spectroscopies, optical absorbance, ferroelectric behavior as well as photoelectrochemical response. Notably, improved photoelectrochemical performance, persistence of the ferroelectric nature and enhanced light absorption could be evidenced highlighting the potential of this new class of materials.
3-Ketoquinolones as new photoinitiators for free radical photopolymerization under LED
Coumarins, and, in particular, 3-ketocoumarins have long been postulated as useful Norrish Type II photoinitiators  but have not found commercial use until the twin problems of solubility in 100% solids UV-curing formulations and reactivity at UV-LED wavelengths were overcome . We present a novel and related set of photoinitiators, based on the 3-ketoquinolone ring structure. Spectroscopic properties, quantum yield in triplet state and efficiency in formation of initiating radicals were measured as well as yellowing and surface curing. Photopolymerization experiments show that 3-ketoquinolones are effective photoinitiators for LED curing.
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.
Emiliano Bonera Università di Milano-Bicocca, Italy
Measuring thermal properties of microscopic materials through Raman spectroscopy and finite-element simulations.
Thermal properties of materials affect their functional properties. The challenging experimental task of measuring the thermal properties of a material is even more complicated when the materials are in the micro and nanoscale range, like in the case of a flake of a bidimensional material, a nanostructure, or a microelectronic device. The difficulties arise from the fact that it might impossibile to electrically contact the material, or because the nanostructure cannot be handled without a substrate or a host that interferes with the measurement.
Methods based on optical micro spectroscopy, such as Raman spectroscopy, can solve this problem with widely diffused experimental setups. The energy and lifetime of phonons are strongly affected by the local temperature. However, the price to pay for this approach is that the measurement is complicated by several factors, and the interpretation requires a comparison with a simulation, which makes the measurement indirect. Even with these drawbacks, however, in many cases the Raman spectroscopy methods remain one of the few possible ways to access the thermal properties on the micrometrical scale. Here we propose a couple of case studies, based on bidimensional materials (e.g. phosphorene) and silicon nanostructure (e.g. nanowires), where we analyse the evolution of position and shape of the Raman spectrum in a system which is locally heated by a continuous laser to get information about the thermal properties of the materials and extract values of thermal conductivity and thermal interface conductance. The results are discussed in terms of reliability and uncertainty.
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.
David Mesguich CIRIMAT, Université Toulouse 3 Paul Sabatier, France
Nanostructured copper-matrix composites for high strength high electrical conductivity applications
The combination of powder metallurgy techniques, spark plasma sintering (SPS) and wire-drawing enables the production of metal and metal-matrix composite cylinders with controlled micro- and nanostructure then wire-drawn to obtain nanostructured wires combining high electrical resistivity and high mechanical strength. These wires can be used for various applications such as high-field magnets or aerospace power and engineering.
Copper-based cylinders prepared by SPS, reinforced by carbon nanotubes or silver microwires, exhibit micrometer-sized grains, typically ten times lower than conventional copper cylinders. Relative density about 90-95% was convenient for the subsequent step of wire-drawing because higher density hampers the deformability of the cylinder, leading to sample breaking.
We will present the samples microstructure at various elaboration steps (powders, SPS cylinders, wires) as well as the evolution of electrical and mechanical properties as a function of wire diameter and composition at 293 K and 77 K. Our results on Ag-Cu wires highlight the benefit in using composite wires instead of alloy wires of similar composition to reach the best compromise between conductivity and strength. These composite materials are now strong candidates for applications such as coil materials in high-field magnets.
Tseung-Yuen Tseng Institute of Electronics, National Yang Ming Chiao Tung University, Taiwan
Zn2SnO4-based optoelectronic synapse device
In this work, we fabricate an optoelectronic synaptic device based on ITO/Zn2SnO4(ZTO)/ITO structure. The fabricated device shows over 80% optical transparency for the entire visible region (400–800 nm). Significant improvements in bipolar resistive switching properties of the device with low SET voltage (+0.93 V) and long DC endurance cycles (~12000) are observed in the 200°C, N2 annealed device. The linearity of such memristive synapse is improved for 350 training epochs with a total number of 175000 pulses. The spike time dependent plasticity learning rule for the annealed device is demonstrated through the electric field. The optical sensing capabilities of this device including photonic potentiation (responsivity: 0.52 µA/W), photonic paired pulse facilitation by adjusting time interval between two identical light pulses, learning experience behavior, and multilevel memory feature by the repetition of optical pulse for ~103 s are demonstrated under the blue light illumination at 50 mW/cm2. Photonic potentiation and electric depression behavior of the device mimics its nonvolatile synaptic plasticity. The I-V curve fitting and energy band diagram illustrate the dominance of Schottky emission and Poole-Frenkel conduction mechanisms at high and low resistance states, respectively. On the other hand, the linearity and on/off ratio of the optoelectronic synapse are further improved by inserting a high bandgap magnesium oxide (MO) layer. Such ZTO/MO memristor device has improved reliability with stable endurance and synaptic characteristics. The proposed device exhibits multilevel switching with varying the reset stop voltages from -1.2 to -2.4 V and the compliance current from 100 to 900 µA. The nonlinearities of potentiation and depression of the device are 1.96 and 0.33, respectively, with 100 conductance states. The device also shows 300 training epochs with 300000 pulse numbers. Such ZTO-based memristors have a high potential for optoelectronic synapse application.
Maria Guseva Topchiev Institute of Petrochemical Synthesis, Russia
Crystallization and compatibility in PP-PE blends
Blends of PP and PE have become a subject of intensive studies both from a purely scientific and practical viewpoint. Preparation and processing techniques for PP-PE systems are well-developed and end-use properties have been studied using various methods. However, there are many aspects in selecting polymers for blending and factors governing compatibility in PP-PE compositions are not entirely understood yet.
In this work, isotactic PP (isotacticity 98%) with Mw = 210 000 was blended with five matrix PEs with different molecular structure. Mw of PEs under study lie in the range of 200 000-300 000 which is quite close to Mw of PP. Viscosity of PEs do not differ significantly. PEs were designated and numbered according to their branching level determined by means of spectroscopy methods. PE1 is a linear polymer (no pendant chains detectable), PE2 has 5 short (methyl and ethyl) groups per 1000 carbon atoms, PE3 – around 20 ethyl branches. PE4 contains 20 pendant groups of different length (from ethyl to octyl) while PE5 has 30 hexyl branches.
It was revealed by DSC that during fast cooling PP crystallized simultaneously with PE1 while in other four blends it crystallized after matrix PE at temperatures much lower than its normal crystallization temperature.
X-ray results revealed ability of PE to modify crystalline structure of isotactic PP. Interaction with highly-branched PE appears to hinder crystallization of PP. Thus in PP-PE6 compositions PP-component does not crystallize and remains mesomorphic. In the matrix of high-density PEs (PE1 and PE2) monoclinic crystals of PP (α-phase) are formed. In blends with PE3 and PE4 PP-inclusions consist of α-crystals and mesomorphic regions with ratio α/meso ≈1/2.
Optical interferometry is going to be used to provide further insight into compatibility between PE and PP.
This study was supported by the Russian Foundation for Basic Research (project no. 20-03-00168-a).
Antoine Elimbi Professor, Cameroon
Chemical composition of amorphous phase on the reactivity of phosphoric acid activation of volcanic ashes.
Inorganic aluminosilicate-based polymers are generally synthesized at ambient or slightly high temperature by alkaline or phosphoric acid activation of aluminosilicate sources. A recent study has shown that, in phosphoric acid activation of volcanic ash, iron is the chemical element mostly dissolved, followed respectively by aluminium, calcium and magnesium while silicon remained inert. However, the latter study did not specify in which phases (crystalline or amorphous) of the precursor these dissolved elements originated from. However, it is well known that either in acidic or alkaline medium, amorphous phase of aluminosilicate is the main concerned. In order to elucidate the effects brought about by chemical composition of amorphous phase in the reactivity of phosphoric acid activation, fresh pastes and hardened products from two volcanic ashes were experimented. The two volcanic ashes differed in mass percentages of oxides in chemical composition of amorphous phase and were activated by various solutions of phosphoric acid (P2O5 / H2O molar ratios between 0.04 and 0.15). It appeared that in one another volcanic ash, amorphous phase was mainly composed of SiO2, Al2O3, CaO, MgO and Fe2O3 oxides. Heat released during activation and initial setting time correlated with the sum of mass percentages (SMP) of Al2O3, Fe2O3, CaO and MgO oxides of amorphous phase: the greater the SMP, the greater was heat released and the lower was initial setting time. Compressive strength increased with the increase of P2O5 / H2O molar ratio up to a limit. Mass percentages of Al2O3 and Fe2O3 oxides in amorphous phase along with P2O5 / H2O molar ratios plaid key roles on the variation and the highest value of compressive strength. Qualitative and quantitative determinations of chemical composition of amorphous phase of volcanic ash are useful parameters allowing getting appreciable view of its reactivity.
Naveed Ahmed Azam Kyoto University, Japan
An inverse QSAR method based on integer linear programming and neural networks
Inferring chemical compounds with desired chemical properties is a hot topic in material informatics that helps in designing/discovering new novel materials. Computer-aided design models have helped significantly to reduce the computation time and cost of inferring new chemical compounds. These models are based on heuristic and statistical algorithms that cause the following problems. These models do not guarantee the optimality of the compounds, i.e., the chemical compounds inferred by these models may not have the closest desired property; output invalid feature vectors that do not correspond to any desired chemical compound; and cannot generate structurally different chemical compounds of a large size. To address these problems, we designed a new model that can guarantee the optimality, always output valid feature vectors, and can generate structurally different chemical compounds of a large size. There are two main phases of our model, namely prediction phase and inference phase. In the prediction phase, our model constructs a prediction function based on an artificial neural network, while in the inference phase, it infers chemical compounds with the desired property. To ensure the optimality and validity of the feature vector in the inference phase, we formulate and solve an integer linear programming formulation. Furthermore, we design an algorithm based on dynamic programming to efficiently generate large chemical compounds. We have tested our method on several chemical properties, and it is evident from the computational results that our model can efficiently infer desired chemical compounds with around 50 atoms.
Gabriella Bognár University of Miskolc, Hungary
New empirical equation for the effective viscosity of nanofluids
Nanofluids are a new type of thermal fluids that are produced by dispersing nanoscale particles in a base fluid. Chemical processing, automobiles, air conditioning, solar panel, and power generation are all examples of heat transfer and fluid flow applications.
In various industrial practices, water, oil, and ethylene/propylene glycol are common thermal fluids used in many engineering applications, including power generation, electronics applications, air conditioning, chemical manufacturing processes, heating, cooling operations, nuclear power system cooling, military, transport, and microelectronic applications.
In practice, nanofluids' thermal conductivity and viscosity are the most important parameters in engineering applications. Viscosity affects pumping performance. Theoretical viscosity correlations are widely used in numerical studies. However, existing correlations show an underestimation of the actual viscosity compared to the measurement results. Although many nanofluid viscosity correlations have been developed, there is no generally accepted correlation. We review the theoretical, numerical, and experimental viscosity correlations and proposes a new correlation based on an analysis of approximately 1,200 experimental and 4,000 theoretical data tested for about 50 types of nanofluids in the temperature range 273-333 K and particle diameters 2-300 nm. The studied volume fraction range for the nanofluids was up to 10%. Existing correlations consider the impact of up to two to three parameters. The new viscosity correlation is proposed to predict the effective viscosity of nanofluids based on regression analysis of theoretical and experimental viscosity results, and it considers several factors that significantly affect the effective viscosity of nanofluids, such as nanoparticle diameter, density, temperature, types of nanoparticles, and base fluid.
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.
Brian Cantor 1Department of Materials, University of Oxford, UK
Multicomponent High-Entropy Cantor alloys
All human advances have depended on making new materials, and all materials are alloys, i.e. mixtures of several different starting materials or components. So the history of the human race has been the continued invention of new materials by discovering new alloys. Recently a new way of doing this, by manufacturing multicomponent high-entropy alloys, has shown that the total number of possible materials is enormous, even more than the number of atoms in the galaxy, so we have lots of wonderful new materials yet to find. And multicomponent phase space contains a surprisingly large number of extended solid solutions. The first group of these which was discovered are called Cantor alloys, an enormous composition range with a single-phase fcc structure, based loosely on the original equiatomic five-component Cantor alloy CrMnFeCoNi. This talk will discuss the previous history of alloying, the discovery of multicomponent alloys, the structure of multicomponent phase space, the fundamental thermodynamics of multicomponent solid solutions such as the Cantor alloys, the complexity of local atomic and nanoscale configurations in such materials, the effect of this on properties such as atomic diffusion, dislocation slip, and the resulting outstanding mechanical properties and potential applications, including at low and high temperatures, for corrosion and radiation resistance, and to enhance recycling and re-use.