Materials Science Research Articles

Optimization of power loss and thermal performance in electric vehicle propulsion: a comparative analysis of Si, SiC, and GaN MOSFET power converters for EESM-based EVs

ABSTRACT This research delves into power loss and thermal dynamics in Si, SiC, and GaN inverters and two-quadrant DC-DC converters for Electric Vehicle (EV) applications with Electrically Excited Synchronous Motors (EESM). Utilizing the Cauer thermal model for dissipating junction temperature through heatsinks, the research unveils semiconductor material performance intricacies. The Si-based inverter exhibits the highest total power loss at 355.49 W, followed by SiC at 164.28 W, and GaN at 139.21 W. The efficiencies of Si, SiC, and GaN-based inverters are calculated as 94.72%, 97.49%, and 97.86%, respectively. Among them, the GaN-based inverter shows the highest efficiency, which is 3.14% higher than that of the Si-based inverter. GaN emerges as the energy-efficient choice, showcasing superior conduction and switching losses for EESM-based EV propulsion. Integration of heatsinks reduces Si average junction temperatures from 199.69 °C to 55.63 °C, SiC from 93.9 °C to 45.97 °C, and GaN from 84.13 °C to 38.78 °C. Enhanced forced cooling and advanced thermal interface materials highlights the critical role of robust thermal management in EESM-based EVs. GaN emerges as the prime candidate for EESM-based EV inverters and DC-DC converters. This research underscores meticulous semiconductor material selection and efficient cooling strategies for optimal performance and reliability.

Methyl side-groups control the Ia3̄d phase in core-non-symmetric aryloyl-hydrazine-based molecules.

Control of the formation of liquid crystalline Ia3̄d gyroid phases and their nanostructures is critical to advance materials chemistry based on the structural feature of three-dimensional helical networks. Here, we present that introducing methyl side-group(s) and slight non-symmetry into aryloyl-hydrazine-based molecules is unexpectedly crucial for their formation and can be a new design strategy through tuning intermolecular interactions: the two chemical modifications in the core portion of the chain-core-chain type molecules effectively lower and extend the Ia3̄d phase temperature ranges with the increased twist angle between neighboring molecules along the network. The detailed analyses of the aggregation structure revealed the change in the core assembly mode from the double-layered core mode of the mother molecule (without methyl groups) to the single-layered core mode. Such changes are explained in terms of modified intermolecular interactions in those phases employing quantum chemical calculations.

Celebrating a New Year with 2024 Highlights at Chemistry of Materials

Celebrating a New Year with 2024 Highlights at Chemistry of Materials

Skeletal Editing through Cycloaddition and Subsequent Cycloreversion Reactions.

ConspectusSkeletal editing, which involves adding, deleting, or substituting single or multiple atoms within ring systems, has emerged as a transformative approach in modern synthetic chemistry. This innovative strategy addresses the ever-present demand for developing new drugs and advanced materials by enabling precise modifications of molecular frameworks without disrupting essential functional complexities. Ideally performed at late stages of synthesis, skeletal editing minimizes the need for the cost- and labor-intensive processes often associated with de novo synthesis, thus accelerating the discovery and optimization of complex molecular architectures. While current efforts in skeletal editing predominantly focus on monatomic-scale modifications, editing molecules through cycloaddition followed by cycloreversion offers a unique strategy to manipulate molecular frameworks on a double-atomic scale. This introduces new possibilities for chemical transformations and enables transformations such as double-atom transmutation, formal single-atom transmutation, and atom insertion. Early examples of such skeletal editing processes often relied on the inherent high reactivity of the substrates, which needed to be sufficiently active to undergo cycloaddition and possess good leaving groups for the subsequent fragmentation (cycloreversion) step. Recently, however, the structural editing of relatively inert substrates has become achievable through substrate activation strategies designed to enhance either the cycloaddition or subsequent cycloreversion step.Along these lines, we recently developed a dearomative process for activating pyridines. In a simple high-yielding chemical operation, oxazinopyridines are readily obtained as activated dearomatized isolable intermediates. This method enabled us to achieve the transformation of pyridines into benzenes and naphthalenes through a cycloaddition/cycloreversion sequence. In this Account, related recent contributions from other research groups are highlighted as well, alongside early examples involving tetrazines, triazines, diazines, and other similar heterocycles as cycloaddition reaction partners. By offering a streamlined route to modify molecular structures, these approaches have demonstrated their ability to interconvert arenes and heteroarenes and have shown significant potential for late-stage editing applications as well as advancing drug discovery and the synthesis of bioactive molecules.In the future, these approaches will undoubtedly see broader development in the field of skeletal editing. New strategies for substrate activation should be devised to enable not only the incorporation of nitrogen and other heteroatoms into rings─rather than their deletion─but also to achieve ring contraction and expand the application of this strategy to non-aromatic rings. We hope that the advancements summarized in this Account will inspire chemists to explore and expand skeletal editing methodologies. By pushing the boundaries of these approaches, researchers can unlock new opportunities for constructing and modifying complex molecular frameworks, eventually paving the way for innovative applications in chemistry, biology, and materials science.

Sequential and Time-Controlled Sol-Gel Transitions by Mechanical Switching of Molecular Tweezers.

Controlling the motion of molecular machines to influence higher-order structures is well-established in biological systems but remains a significant challenge for synthetic analogs. Herein, we aim to harness the mechanical switching of switchable molecular tweezers to modulate their self-assembly and produce stimuli-responsive organogels. We report a series of terpy(Pt-salphen)2 molecular tweezers functionalized with alkyl chains that act as low-molecular-weight gelators (LMWGs) in their open conformation. The resulting organogels were thoroughly characterized by SEM, cryo-TEM, SAXS, and rheology. The macroscopic transition from gel to solution was achieved by the cation-induced closing of the tweezers, which triggers their substantial structural reorganization. Reversible sol-gel transitions were achieved through the sequential addition of chemical stimuli or by a decomposable acid in a time-controlled operation. Such transient disassembly process regulated by a chemical fuel enables multiple gelation cycles with minimal waste while maintaining stable rheological properties. These results underscore the potential of switchable molecular tweezers in creating advanced stimuli-responsive materials.

Discovery of new topological insulators and semimetals using deep generative models

Topological materials possess unique electronic properties and hold immense attraction to both fundamental physics research and practical applications. Over the past decades, the discovery of new topological materials has relied on the symmetry-based analysis of the quantum wave function. In this study, we propose an efficient inverse design method CTMT (CTMT: CDVAE, Topogivity, interatomic potentials (IAPs) as realized in M3GNet, and TQC) utilizing deep generative machine learning models to discover novel topological insulators and semimetals in a much-fast and low-cost manner. This method covers the entire process of new crystal structure generation, heuristic rule screening, fast stability estimation, and topology type diagnosis, resulting in 4 topological insulators and 16 topological semimetals. Especially, the newly discovered topological materials include several chiral Kramers-Weyl fermion semimetals and chiral materials with low symmetry, whose topology is previously considered challenging to discern. These findings demonstrate the capability of CTMT in discovering topological materials and its great potential for data-driven inverse design of advanced functional materials.

Designing High-Damping, Optically Clear Ionogels through Competitive Binding for Flexible and Impact-Resistant Applications.

Developing damping materials that are both optically transparent and mechanically robust, while offering broad frequency damping capacity, is a significant challenge─particularly for devices that require protection without compromising visual clarity. Conventional methods often either fail to maintain transparency or involve complex designs that are difficult to implement. Here, we present an ionogel system that integrates a physically cross-linked elastic copolymer network with a viscous ionic liquid. The competitive interactions between the ionic liquid and the polymer network enable fine-tuning of the mechanical stability and damping capacity. The resulting ionogel is transparent and mechanically robust and exhibits excellent damping over a wide frequency range. Remarkably, a thin layer (0.15 mm) absorbs nearly 60% of the impact force and retains its performance after exposure to extreme conditions. This approach offers a straightforward method for designing advanced damping materials that meet both the aesthetic and functional demands of modern technologies.

2D WS2 monolayer preparation method and research progress in the field of optoelectronics.

Two-dimensional Transition Metal Dichalcogenides (2D TMDs) have garnered significant attention in the field of materials science due to their remarkable electronic and optoelectronic properties, including high carrier mobility and tunable band gaps. Despite the extensive research on various TMDs, there remains a notable gap in understanding the synthesis techniques and their implications for the practical application of monolayer tungsten disulfide (WS2) in optoelectronic devices. This gap is critical, as the successful integration of WS2 into commercial technologies hinges on the development of reliable synthesis methods that ensure high quality and uniformity of the material. In this study, we present a comprehensive overview of the synthesis techniques for monolayer WS2, focusing on mechanical stripping, Atomic Layer Deposition (ALD), and Chemical Vapor Deposition (CVD). We highlight the advantages of each method, such as the uniform growth achievable with ALD at low temperatures and the capability of CVD to produce large-area, high-quality monolayers. Additionally, we summarize the performance of WS2 in various electronic and optoelectronic applications, including field-effect transistors (FETs), photodetectors, and logic devices. Our findings indicate that with ongoing advancements in film uniformity, compatibility with existing semiconductor processes, and the long-term stability of WS2-based devices, there is a promising trajectory for the transition of 2D WS2 from laboratory research to practical applications. This work not only addresses the existing gaps in the literature but also underscores the potential of WS2 to significantly impact the future of optoelectronic technologies.&#xD.

Unlocking hexafluoroisopropanol as a practical anion-binding catalyst for living cationic polymerization.

Living cationic polymerization (LCP) is a classical technique for precision polymer synthesis; however, due to the high sensitivity of cationic active species towards chain-transfer/termination events, it is notoriously difficult to control polymerization under mild conditions, which inhibits its progress in advanced materials engineering. Here, we unlock a practical anion-binding catalytic strategy to address the historical dilemma in LCP. Our experimental and mechanistic studies demonstrate that commercially accessible hexafluoroisopropanol (HFIP), when used in high loading, can create higher-order HFIP aggregates to tame dormant-active species equilibrium via non-covalent anion-binding principle, in turninducingdistinctive polymerization kinetics behaviors that grant efficient chain propagation while minimizing competitive side reactions. This unique control mechanismdelivers unprecedented polymerization activity and controllability across various electron-rich vinyl monomers under mild conditions, and provides easy access to high molecular weight polymers, block copolymers, and end-functionalized telechelic polymers. Also, the minimalistic structure of HFIP coupled with its convenient removal and recycle renders this approach easy to scale up, without concern for cost, sustainability and complicated work-up processes associated with previous systems. This study presents another universal and sustainable strategy for cationic macromolecular engineering, and will also stimulate further exploration of innovative non-covalent catalysis that enables more challenging living polymerization systems.

Tailorable biosensors for real-time monitoring of stress distribution in soft biomaterials and living tissues

Visualizing mechanical stress distribution in soft and live biomaterials is essential for understanding biological processes and improving material design. However, it remains challenging due to their complexity, dynamic nature, and sensitivity requirements, necessitating innovative techniques. Since polysaccharides are common in various biomaterials, a biosensor integrating a Förster resonance energy transfer (FRET)-based tension sensor module and carbohydrate-binding modules (FTSM-CBM) has been designed for real-time monitoring of the stress distribution of these biomaterials. By simple dripping or soaking, FTSM-CBM enables fast, reproducible and semiquantitative detection of both 2D and 3D stress distributions in polysaccharide-based hydrogels. Additionally, it provides valuable information such as microstructure hints and fracture site warnings. FTSM-CBM can also monitor the locomotion of maggots, which is not feasible with most existing techniques. Furthermore, by changing the CBM, FTSM-CBM can be expanded for various polysaccharide-based biomaterials. This study provides a powerful tool that may promote related research in life and materials science.

Synthesis and Performance of Epoxy-Terminated Hyperbranched Polymers Based on Epoxidized Soybean Oil

Epoxy-terminated hyperbranched polymers (EHBPs) are a class of macromolecular polymers with a hyperbranched structure containing epoxy groups. They possess characteristics such as low viscosity, high functionality, and thermal stability, which endow them with broad application potential in materials science and chemical engineering. This study uses epoxidized soybean oil (ESO) as the raw material, which undergoes ring-opening reactions with glycerol and is esterified with 2,2-bis(hydroxymethyl)propionic acid (DMPA) to obtain epoxy soybean oil polyol (EGD) with a high hydroxyl value. Subsequently, four types of EHBPs are synthesized by incorporating epichlorohydrin (ECH) in mass ratios of 1:3, 1:4, 1:5, and 1:6 under strong alkaline conditions. The product structure is characterized using FT–IR and GPC. The degree of branching of EGD is calculated using 1H NMR and 13C NMR spectroscopy. The epoxy value of EHBPs is tested using the hydrochloric acid–acetone method, and the water contact angle, adhesion properties, rheological properties, and thermal properties of the EHBPs are also evaluated. The results show that the degree of branching of EGD is 0.45. The epoxy values of the EHBPs are 0.73, 0.79, 0.82, and 0.89 mol/100g, respectively. As the epoxy value and molecular weight of the epoxy hyperbranched polymers (EHBPs) increase, the water contact angle and adhesion strength of the EHBPs rise progressively and the viscosity decreases. Additionally, the glass transition temperature increases with the increase in the epoxy value. These epoxy hyperbranched polymers with low viscosity and high adhesion strength offer a promising approach for modifying surface coatings or formulating adhesives.

Emissive Bovine Serum Albumin‐Templated Osmium Nanoclusters: Synthesis and Optical Characterization

Synthesis of new nanomaterials with unique optical properties is of great importance in different fields such as energy, material science, and biomedicine. Here, for the first time, we report the synthesis of the emissive osmium nanoclusters (OsNCs) using bovine serum albumin (BSA) as template and sodium borohydride as strong reducing agent. The as‐synthesized emissive OsNCs had only 31 atoms, with deep‐blue color emission with an emission maximum at 415 nm and a photoluminescence quantum yield (PLQY) of 2.5%. The fluorescence emission of OsNCs could be attributed to the smaller number of atoms (31) in the as‐synthesized OsNCs in this work. The optical characterization of the emissive OsNCs revealed that the fluorescence intensity was more sensitive to pH than with temperature of the solution. When pH was increased from 1 to 12, there was 6‐fold increase in the emission intensity. We believe that the presented synthesis route as well as the results of this work could open new avenues to further investigate the OsNCs as new emissive nanomaterials and their potential applications in biomedical and energy fields.

Engineering Group VI Transition Metal Dichalcogenides for Designing Various Sensors

AbstractRecent advancements in sensor technology are driven by progress in materials science and increasing demands from applications such as health diagnostics. Particularly, with the push from nanotechnology and biocompatible materials, sensor technology has made significant progress. Sensor applications have been greatly enhanced by the unique properties of transition metal dichalcogenides (TMDs). These high‐performance sensors not only improve the accuracy of measurements but also provide robust support for real‐time data analysis. To further demonstrate the latest advancements in sensor technology, this paper specifically introduces the recent researches of sensors based on WS2, MoS2, and their composites. Herein, the structures and the properties of TMDs are systematically described, highlighting their strong potential for advancing sensor development. Then, the recent progress of Group VI TMDs in various sensor domains, including humidity sensors, temperature sensors, gas sensors, biosensors, image sensors, and strain sensors, is further discussed. Through detailed analysis of the function and performance of Group VI TMDs in these areas, this paper aims to emphasize their advantages as sensor materials. The performance of TMDs in various sensor applications is also systematically summarized, and a glimpse into what the future holds for sensors using TMDs is offered.

Editorial for “Mechanical Behavior of Concrete Materials and Structures: Experimental Evidence and Analytical Models (Volume II)”

Concrete represents one of the most popular materials employed in the civil engineering sector due to its flexibility and adaptability to multiple applications, ranging from non-structural elements and partition walls to structural elements and load-bearing members. However, various applications require specific characteristics of concrete and motivate the development of new mix designs, additives, advanced materials and construction practices, which widen the scope of research on concrete engineering in general [...]

Active oversight and quality control in standard Bayesian optimization for autonomous experiments

The fusion of experimental automation and machine learning has catalyzed a new era in materials research, prominently featuring Gaussian Process (GP) Bayesian Optimization (BO) driven autonomous experiments. Here we introduce a Dual-GP approach that enhances traditional GPBO by adding a secondary surrogate model to dynamically constrain the experimental space based on real-time assessments of the raw experimental data. This Dual-GP approach enhances the optimization efficiency of traditional GPBO by isolating more promising space for BO sampling and more valuable experimental data for primary GP training. We also incorporate a flexible, human-in-the-loop intervention method in the Dual-GP workflow to adjust for unanticipated results. We demonstrate the effectiveness of the Dual-GP model with synthetic model data and implement this approach in autonomous pulsed laser deposition experimental data. This Dual-GP approach has broad applicability in diverse GPBO-driven experimental settings, providing a more adaptable and precise framework for refining autonomous experimentation for more efficient optimization.

АНАЛИЗ СОДЕРЖАНИЯ ВИТАМИНА С В МЕСТНЫХ ПРОДУКТАХ ПИТАНИЯ ЯКУТИИ

he purpose of the study is to analyze the content of vitamin C in the most consumed food products and wild berries by the population of Yakutia. The object of research is products of animal and plant origin, wild berries. The research material was collected in 2016–2019 in Central Yakutia. Selection and preparation of samples were carried out according to the method of A.F. Abramova (2007). The content of vitamin C in food products was determined by infrared spectroscopy on a SpectraStar 2200 analyzer, calibrated on the basis of standard chemical methods, in the laboratory of agricultural products processing and biochemical analyzes of the Yaroslavl Research Institute of Agriculture. The norms for vitamin C requirements per day vary by population group, in accordance with the norms of physiological needs: for children – from 30 to 90 mg/day, for adults – 100 mg/day. Among animal foods, the richest in vitamin C are mare's milk (11.4 mg/100 g), fermented milk product "Ot Uerete" (1.6 mg/100 g), and among plant products – green crops (parsley (150.0 mg/ 100 g), dill (100.0 mg/100 g), onion (95.0 mg/100 g), among wild berries, the highest content of vitamin C was noted in rose hips (3100.0 mg/100 g) and black currants (386.0 mg/100 g). When consuming 250 g of mare's milk, the degree of satisfaction in vitamin C can be 28.5 % according to MP 2.3.1.0253-21. A serving (100 g) of cabbage and potatoes satisfies the daily requirement of an adult for vitamin C by 45 and 10 %.

ВЛИЯНИЕ КОНТАМИНИРОВАННОГО МИКОТОКСИНАМИ КОРМА И ПРОТИВОПАРАЗИТАРНОЙ ОБРАБОТКИ ЭПРИНОМЕКТИНОМ НА КИШЕЧНУЮ МИКРОБИОТУ ЖИВОТНЫХ В УСЛОВИЯХ ЭКСПЕРИМЕНТА

Animals are exposed to numerous stress factors in industrial conditions. The greatest danger is posed by mycotoxins that change the composition of the microbiota in animals, which is one of the reasons for the development of immunosuppression. The purpose of the study is to establish changes in the composition of the intestinal microbiota in laboratory animals with combined contamination of feed with mycotoxins and antiparasitic treatment with eprinomectin. The study was conducted on laboratory rats (five groups of 10 rats each). Animals of the 1st group received a standardized diet and were not exposed to mycotoxins and eprinomectin, the 2nd, 3rd, 4th and 5th groups of animals received food containing mycotoxins (DON – 0.93, T-2 – 0.025; ZEA – less than 0.02 mg/kg). Additionally, animals of the 3rd and 5th groups were subjected to a single antiparasitic treatment with the drug Veteprin (active ingredient – eprinomectin). Enterosorbent modified with polyarginine was administered daily with food to animals of groups 4 and 5 at a dose of 0.2 g/kg for 12 days at the final stage of the experiment lasting 50 days. The material for bacteriological research was samples of the contents of the cecum. The luminal microflora of the cecum in all animals is dominated by Bifidobactererium spp. and Lactobacillus spp. However, a noticeable decrease in their number is observed with the combined effect of eprinomectin and mycotoxins on the animal body, which indicates a decrease in colonization resistance and inhibition of parietal digestion. Against the background of a decrease in the proportion of obligate anaerobic microflora in the intestine, the number of facultative opportunistic microorganisms increases. Increased growth of yeast-like fungi in the intestine indicates decreased immune reactivity and impaired intestinal barrier function. The use of a sorbent modified with polyarginine normalizes and stabilizes the intestinal microflora.

Condition Surveys as the Basis for Scientific Research and with the Aim of Conserving Torso Buildings

Condition surveys are an important part of the whole scientific research of torso buildings, which we understand to be buildings with usually missing roofs, wooden ceilings, doors, windows, and other envelope constructions along with damaged internal and external infrastructure and surfaces. The aim of the processed condition surveys is to gather basic data on the technical state of the buildings. Torso buildings are, in our environment, especially the ruins of castles and manor houses, but also some churches, the remains of industrial enterprises, or even others. The proposed condition surveys can be used at any of them, not only in our country, but also in any other country of the world. The processed system of condition surveys allows us to anticipate further damage to architectural heritage buildings caused by their aging. It can contribute in a major way to the identification of eventual construction risks and to anticipate them. Condition surveys are designed as a quick, cheap, and easy to handle way to gather the basic overview needed for undertaking a basic stabilization of the most endangered parts of the ruins. In the next step, further scientific research using instruments i.e., in laboratories, can be undertaken. It is also important to know which parts of the torso buildings are dangerous and can endanger not only visitors, but also scientists realizing research on site. The first goal of the project focused on bettering of the stability of the torso buildings, especially ruins of castles, which was granted by the Slovak Ministry of Culture to elaborate and prepare a system for the identification of the most endangered parts of the ruins, which are in danger of dilapidation soon. The second goal was focused on preparing source material for further scientific research of the torso architecture. Experts from the Faculty of Civil Engineering of the Slovak University of Technology, with the cooperation of experts from praxis and from the Architectural Heritage Protection Office prepared a system for judging the construction details of torso buildings from the point of view of their construction–technical state. The aim of this judging lies in identifying the parts of their constructions that are most endangered by decay. Based on the condition survey results, conservation activities can be organized to save valuable details of the torso buildings before destruction and to protect the visitors of such localities before injuries, maybe even tragic injuries.

Force‐Trainable Liquid Crystal Elastomer Enabled by Mechanophore‐Induced Radical Polymerization

In nature, organisms adapt to environmental changes through training to learn new abilities, offering valuable insights for developing intelligent materials. However, replicating this adaptive learning in synthetic materials presents a significant challenge. This study introduces a feasible approach to train liquid crystal elastomers (LCEs) by integrating a mechanophore tetraarylsuccinonitrile (TASN) into their main chain, addressing the challenge of enabling synthetic materials to exchange substances with their environment. Inspired by biological training, the LCEs can self‐strengthen and acquire new functionalities through mechanical stress‐induced radical polymerization. The research not only enhances the mechanical performance of LCEs, but also endows them with the ability to learn properties such as flexibility, light responsiveness, and fluorescence. These advancements are crucial for overcoming the limitations of current materials, paving the way for the creation of advanced intelligent soft materials with autonomous self‐improvement, akin to the adaptive skills of living organisms.

Force-Trainable Liquid Crystal Elastomer Enabled by Mechanophore-Induced Radical Polymerization.

In nature, organisms adapt to environmental changes through training to learn new abilities, offering valuable insights for developing intelligent materials. However, replicating this adaptive learning in synthetic materials presents a significant challenge. This study introduces a feasible approach to train liquid crystal elastomers (LCEs) by integrating a mechanophore tetraarylsuccinonitrile (TASN) into their main chain, addressing the challenge of enabling synthetic materials to exchange substances with their environment. Inspired by biological training, the LCEs can self-strengthen and acquire new functionalities through mechanical stress-induced radical polymerization. The research not only enhances the mechanical performance of LCEs, but also endows them with the ability to learn properties such as flexibility, light responsiveness, and fluorescence. These advancements are crucial for overcoming the limitations of current materials, paving the way for the creation of advanced intelligent soft materials with autonomous self-improvement, akin to the adaptive skills of living organisms.