Chemistry and Materials Science

Abstract:

Porous BaTiO₃ (BTO) ceramics with controlled porosity were successfully fabricated using a simple and cost-effective sucrose-assisted route. Porosity was introduced by incorporating 10–50 vol% sucrose as a pore-forming agent, followed by sintering at 1350 °C for 2 h. The use of sucrose as an effective pore-forming agent is corroborated by the systematic reduction in bulk density from ~5.92 to ~4.1 g.cm^-3. X-ray diffraction and Raman spectroscopy analysis revealed the retention of the tetragonal phase across all samples, indicating that the introduction of porosity does not alter either the average crystal or local structure. Microstructural analysis demonstrated well-developed grains with heterogeneously distributed and interconnected porosity upon sucrose addition, while maintaining good grain connectivity. Electrical characterisation showed a gradual decrease in maximum polarisation (P_max) from ~21 µC.cm^-2 for dense BTO to ~12 µC.cm^-2 for 50 vol% sucrose samples. Despite increased porosity, the electric field-induced strain response exhibited only a marginal reduction (~0.137% to 0.10%), indicating preserved electromechanical functionality with enhanced large-signal piezoelectric coefficient ~468 pm.V^-1 for the 20 vol% sucrose sample, whereas the 10 vol% counterpart shows the largest ɛ_RT ~1150 with tan δ = 0.005. These results demonstrate that sucrose-assisted fabrication enables effective porosity engineering in BTO without compromising its ferroelectric nature, offering a promising approach for the development of porous ferroelectric ceramics with tunable electromechanical properties.

Abstract: Carbon fiber reinforced epoxy resin composites were manufactured using the vacuum infusion technique. Composite samples were subjected to impact and then exposed to various weathering conditions. Static and dynamic mechanical tests were performed to evaluate the effect of an additional process step, a plasma treatment of the carbon fiber fabric before the composite is manufactured. Scanning electron microscopy and thermal analysis were used to get further information on the degree of damage after weathering. Treating the reinforcing carbon fibers with air plasma resulted in improved strength values and fatigue behavior of the epoxy resin composite. This performance enhancement persisted even after a low-energy mechanical stress and subsequent weathering.

Abstract: Multilayer ceramic batteries (MLCBs) have emerged as promising chip-type all-solid-state energy-storage devices that combine the safety and thermal stability of oxide ceramic batteries with the manufacturing scalability of multilayer ceramic capacitor (MLCC) technologies. Demand for miniaturized, reliable, and thermally robust power sources in Internet of Things (IoT) systems, wearable electronics, autonomous sensors, and AI-driven edge devices has accelerated interest in ceramic-based multilayer energy-storage architectures. Unlike conventional lithium-ion batteries using flammable liquid electrolytes, MLCBs employ solid ceramic structures that improve nonflammability, thermal stability, and surface-mount-device (SMD) compatibility. This review summarizes recent advances in MLCB technologies, focusing on oxide solid electrolytes, cathode and anode materials, multilayer ceramic manufacturing, co-firing science, interface engineering, and reliability. Key manufacturing challenges include lithium volatilization, shrinkage mismatch, interfacial reactions, pore formation, and stress-induced delamination during multilayer co-sintering. Future directions such as low-temperature co-firing, glass-assisted or hybrid oxide electrolytes, and AI-driven smart manufacturing are discussed. MLCBs are therefore positioned not as miniaturized MLCCs, but as ceramic-integrated electrochemical energy platforms enabled by convergence of MLCC infrastructure and solid-state battery technologies. Unlike conventional solid-state-battery materials reviews, this work emphasizes MLCBs as manufacturing-constrained multilayer ceramic electrochemical systems in which electrolyte chemistry, electrode compatibility, co-firing atmosphere, interfacial reactions, and mechanical reliability must be co-designed.

Abstract: Glass-ceramic foams (BVZ: bottle glass waste–zirconia residue–bentonite) were produced using the polymeric replica method from low-cost raw materials, comprising approximately 85 wt% bottle glass waste and zirconia residue, and 15 wt% regional bentonite. To evaluate the effect of zirconia residue on the microstructure and physicochemical properties of the BVZ foams, aqueous precursor suspensions were prepared with varying proportions of bottle glass waste (59.7–69.7 wt%) and zirconia residue (14.9–19.9 wt%), and sintered at 750 °C, 800 °C, and 850 °C. X-ray diffraction (XRD) analysis revealed a reduction of the amorphous halo (15–35° 2θ) and an increase in crystallinity with increasing temperature, indicating devitrification of the glassy matrix. The main crystalline phases identified were zircon (ZrSiO₄), nepheline (NaAlSiO₄), AlPO₄, and zirconia (ZrO₂), with evidence of minor domains structurally compatible with NASICON-type phases (NaZr₂(PO₄)₃). In general, glass-ceramic foams produced with high waste content showed greater densification and reduced porosity at 850 °C. The mechanical strength was sufficient for handling and assembly in electrochemical cell components, while the reduced brittleness supports safe processing and indicates potential for scalable manufacturing.

Abstract: Silicon carbide (SiC) nanowires possess unique one-dimensional structural features, excellent mechanical strength, thermal stability and wide bandgap properties, showing great potential in high-temperature electronics, catalysis, sensing and composite reinforcement. Nevertheless, pristine SiC nanowires suffer from inert surface activity, weak interfacial compatibility and limited optoelectronic and catalytic performance. Surface coating and heterojunction engineering are effective strategies to address these deficiencies. This review systematically summarizes the synthesis routes of pristine SiC nanowires, including carbothermal reduction, chemical vapor deposition, template-assisted growth and molten salt synthesis, as well as their morphological regulation, physicochemical properties and inherent limitations. Meanwhile, typical coating methods such as wet chemical, hydrothermal, CVD and PIP are elaborated, and the influences of coating thickness, uniformity, adhesion and lattice/thermal compatibility on performance are summarized. The classification and interfacial charge mechanism of Type II, Z-scheme and Schottky heterojunctions are discussed, and the advances of coated SiC nanowires in photodetection, photocatalysis, gas sensing, electromagnetic shielding and energy storage are reviewed. Current challenges including coating stability, scalable preparation and integration bottlenecks are pointed out, and future research directions focusing on interface control, multifunctional integration and AI-assisted material design are prospected.

Abstract: Additive manufacturing using vat photopolymerization (VPP) resin materials has gained attention for fabricating dental prostheses; however, the effects of material type and build angle on their properties remain unclear. We compared the mechanical properties of two filler-containing VPP hybrid resins, SprintRay Ceramic Crown (CC) and OnX Tough 2 (OT), with those of a conventional polymethyl methacrylate (PMMA) disc material, and evaluated the influence of build angle on surface characteristics, dimensional accuracy, and mechanical performance. Specimens were fabricated using a DLP system at build angles of 0°, 45°, and 90°. Vickers hardness, surface morphology and roughness, dimensional deviations, flexural strength, elastic modulus, and fracture energy were assessed according to relevant standards. CC exhibited significantly higher hardness and elastic modulus than PMMA and OT, whereas OT showed the highest fracture energy. Surface morphology and roughness were strongly affected by build angle, with 45° producing distinct periodic patterns and increased roughness. Dimensional evaluation revealed a tendency toward overbuilding, particularly in the vertical direction at 45°. Flexural properties were also influenced by build angle, with 45° generally providing favorable performance. Both material composition and build angle affect VPP-fabricated dental resin performance, highlighting the importance of appropriate material and processing selection for clinical applications.

Abstract: This work reports the synthesis, characterization, and photocatalytic performance of mul-tifunctional spheres based on AgNPs-doped TiO2-Fe3O4 embedded in an alginate-chitosan biopolymeric matrix for the removal of organic contaminants from water. The composite powders exhibited a nanocrystalline structure composed of anatase TiO2 (~20 nm) and magnetite (~25 nm), with homogeneously dispersed Ag nanoparticles, as observed by SEM. The spheres presented a mainly submicrometric particle size distribution (0.55-0.92 µm), favoring high surface area and colloidal stability. Under simulated solar irradiation, the material achieved efficient photocatalytic degradation of methylene blue, with a pseu-do-first-order rate constant of 0.112 h⁻¹ and ~46 % decolorization after 5 h. UV-Vis spectra showed progressive attenuation of the dye absorption band without accumulation of in-termediates. The spheres also exhibited strong antibacterial activity, reaching 87 % reduc-tion of total coliforms and >93 % of fecal coliforms after 5 h of irradiation. Magnetic recov-ery tests confirmed rapid separation and reuse without performance loss. The enhanced activity is attributed to the synergistic interaction among plasmonic Ag, photocatalytic TiO2, redox-active Fe3O4, and the adsorptive carbon-biopolymer matrix. The material ex-hibited strong antibacterial activity, achieving over 90% removal of fecal coliforms after 5 h of irradiation Therefore, the developed AgNPs-doped TiO2-Fe3O4 spheres represent a sus-tainable, reusable and efficient material for solar-assisted water sanitation.

Abstract: This study investigates the energy-efficient mechanochemical activation of fly ash derived from Kazakh coals for the development of sustainable cementitious composites. The ap-proach aims to enhance the reactivity of aluminosilicate materials while reducing the en-ergy demand and carbon footprint associated with conventional clinker-based cement production. Mechanochemical activation was performed to increase the specific surface area and in-duce structural defects in the glassy phase of fly ash, thereby improving its reactivity. Chemical activation using sodium hydroxide (NaOH) was applied to promote intensive pozzolanic reactions and accelerate dissolution kinetics. The optimal activation conditions were identified as 15 min of mechanical treatment com-bined with 4% NaOH. Under these conditions, the compressive strength reached 35.5 MPa at 28 days, exceeding that of the reference cement (35.0 MPa). At fly ash contents of 15–20%, the composites maintained or improved strength, whereas an increase to 30% resulted in a reduction to 31.5 MPa. Mechanical activation increased the specific surface area to approximately 4800–5000 cm²/g; however, prolonged grinding (up to 30 min) led to particle agglomeration and a de-crease in strength to about 28 MPa. Chemical activation enhanced reaction kinetics without significantly affecting particle fineness. Microstructural analysis revealed the formation of a dense and homogeneous matrix dom-inated by C–S–H, C–A–S–H, and N–A–S–H gel phases with reduced porosity. The com-bined activation approach demonstrated a clear synergistic effect, enabling up to 20% ce-ment replacement without loss of performance. Importantly, the proposed method provides a low-energy pathway for the utilization of industrial waste, contributing to reduced clinker consumption and lower CO₂ emissions. The results highlight the significant potential of Kazakhstan’s industrial by-products for the production of energy-efficient, environmentally friendly, and cost-effective construction materials.

Abstract: Composite components with variable thickness structures often suffer from insufficient forming pressure during curing due to complex pressure transfer in regions with abrupt thickness changes, which easily causes void defects and degrades component performance. In this study, a mechanical vibration-assisted double vacuum bag process is proposed. Finite element analysis of the vibration energy field in saturated porous composites is conducted, and curing experiments for variable-thickness specimens are designed. The effects of vibration, vacuum, and their synergy on void characteristics and mechanical properties are studied using microscopic characterization and mechanical tests. The results indicate that vibration can effectively facilitate gas discharge and accelerate resin flow, while the double vacuum bag process reduces gas discharge resistance in the early curing stage by delaying the vacuum negative pressure application, yet it also results in insufficient resin flow due to this delay. Through the synergistic optimization of vibration-assisted energy field parameters and the double vacuum bag process, gas-induced and flow-induced voids can be effectively suppressed while ensuring curing efficiency, reducing the macroscopic porosity of variable-thickness regions from 8.34% (single vacuum bag process) to 0.43%. This study provides a new approach for the high-quality curing and manufacturing of variable-thickness composite components.

Abstract: Metal-supported solid oxide fuel cells (MS-SOFCs) represent a promising advancement for intermediate-temperature energy conversion applications due to their enhanced mechanical robustness and rapid startup capabilities. This investigation systematically evaluates the correlation between yttria-stabilized zirconia (8YSZ) electrolyte thickness and electrochemical performance in Ni-Fe supported architectures. Three distinct cells featuring YSZ electrolyte thicknesses of 7.05, 14.2, and 21.2 μm were fabricated via tape casting and co-sintering at 1350°C, maintaining identical Ni-Fe support (280 μm) and Ni-YSZ anode (22 μm) thicknesses. Electrochemical characterizations revealed a clear inverse relationship between electrolyte thickness and cell performance. The cell with the thinnest electrolyte (7.05 μm) achieved the highest power density of 0.32 W/cm² at 800°C, representing a 4.6-fold improvement compared to the thickest variant (21.2 μm). Electrochemical Impedance Spectroscopy and Distribution of Relaxation Times analysis confirmed that ohmic resistance dominated the total cell impedance, scaling linearly with electrolyte thickness while electrode kinetics remained consistent. This study establishes that thin YSZ electrolytes (≤8 μm) maximize MS-SOFC performance while maintaining structural integrity through co-sintering fabrication, providing an essential design for high-performance metal-supported fuel cell development.

Abstract: The solidification process is crucial for preparing high-performance ceramic super-conductor. The solidification process is strongly dependent on the characteristics of the starting powder, including particle size, morphology, and phase purity. This review concisely examines the study on four key ceramic superconductors: REBCO, Bi-2212, FeSeTe, and MgB₂. In REBCO, additives such as CeO₂, Pt, or BaO₂ powder can refine the RE-211 phase. In Bi-2212, Pb or Nb powder additions stabilize the high-T_c phase. For FeSeTe, doping with F or Co modifies phase separation and introduces Δκ pinning. Meanwhile, in MgB₂, the incorporation of SiC nanoparticles powder generates effective pinning centers. Concurrently, processing conditions exert a decisive influence on the final microstructure, as demonstrated by the TSMG/TSIG route in REBCO, partial melting parameters for Bi-2212, specific cooling protocols and thermal treatments for FeSeTe, and optimized sintering and post-annealing processes for MgB₂. Future research directions should prioritize fundamental understanding of phase separation mechanisms during powder processing, development of multi-component doping strategies for powder modification, and advancement of scalable powder processing routes for practical conductor architectures.

Abstract: This study investigates the effect of progressive CaO/SrO substitution on the structure, crystallisation behaviour, and coordination chemistry of fluorapatite-forming glass-ceramics in the SiO₂–Al₂O₃–P₂O₅–CaO/SrO–CaF₂ system. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), ATR-FTIR spectroscopy, ³¹P and ¹⁹F MAS-NMR, and transmission electron microscopy (TEM) were employed to probe both crystallisation and local structural environments. Increasing SrO content reduced the glass transition temperature and suppressed homogenous nucleation, promoting surface-nucleated fluorapatite (Ca5−x​Srx​(PO4​)3​F) formation. XRD confirmed fluorapatite as the primary crystalline phase and revealed systematic lattice expansion consistent with partial Sr²⁺ incorporation. ¹⁹F MAS-NMR indicated limited Sr substitution at Ca(II) sites (solid-solution), while ³¹P MAS-NMR demonstrated pronounced phosphorus deshielding, reflecting sensitivity of phosphate tetrahedra to local coordination distortion rather than extensive Sr occupancy. Integrating these findings provides a comprehensive framework for interpreting structural and coordination changes in Sr-fluorapatite glass-ceramics.

Abstract: The aim of this study was to investigate the adhesion of primary colonizers of the oral biofilm on five adhesive restorative materials. For each material (Admira Fusion, Clearfil AP-X, Durafill VS, Filtek Supreme XTE, Venus Diamond) sixteen test specimens were prepared according to a standardized protocol. For pellicle formation, the specimens were incubated for two hours at 37 °C with sterile-filtered inactivated human saliva. The bacteria (S. oralis, S. gordonii, S. sanguinis, S. mitis, A. spp.) were cultivated and suspended. A bacteria mix was prepared from the suspensions. The specimens with pellicles were wetted with the bacterial mix and incubated at 37 °C for 8 hours. The total genomic DNA of the adhered bacteria was isolated and subsequently quantified using SYBR Green qPCR. For S. gordonii, S. oralis and A. spp., no significant differences in the amount of adhered bacterial DNA were found between the different materials. DNA concentration of S. mitis was significantly higher on Filtek Supreme XTE compared to the other materials. Significantly higher DNA concentrations of S.sanguinis could also be detected on Filtek Supreme XTE compared to Clearfil AP-AX and Durafill VS.

Abstract: This study aimed to develop a recycling process for reintegrating dental zirconia waste into CAD/CAM systems and to demonstrate the feasibility of producing functional products from the recycled material. The process began with the purification of zirco-nia, followed by the fabrication of pre sintered blocks compatible with these systems. Subsequently, sintered commercial and recycled zirconia were characterized and compared through density measurements, Vickers hardness, flexural strength, X ray diffraction, hydrothermal degradation analysis, and scanning electron microscopy. The results showed that recycled zirconia exhibits structural properties suitable for practi-cal applications, enabling the fabrication of several industrial prototypes. Overall, this work demonstrates that high value materials such as zirconia can be successfully recy-cled and reintegrated into manufacturing workflows, thereby reducing harmful waste while contributing to environmental sustainability and cost reduction.

Abstract: The increasing occurrence of persistent and bio-recalcitrant organic pollutants in aquatic environments necessitates the development of more resilient and efficient water treatment technologies. Conventional treatment processes often fail to remove such stable contaminants, prompting growing interest in integrated advanced systems. Photocatalytic membranes represent a promising solution due to the synergistic combination of separation and catalytic degradation. In this study, ZnO thin films were deposited by spin coating onto smectite–zeolite ceramic membranes (MS10/Z90), with one to three layers applied to control catalyst thickness (M1–M3). SEM analysis showed that increasing the number of layers led to a thicker, more homogeneous ZnO coating, while XRD confirmed enhanced crystallinity and larger crystallite size. Water permeability decreased from 623 L.h-1.m-2.bar-1 for the uncoated MS10/Z90 membrane to 506, 439, and 350 L.h-1.m-2.bar-1 respectively for M1, M2, and M3 after coating. Photocatalytic performance was assessed using Rhodamine B (RhB) as a model dye, achieving degradation efficiencies of 83.0%, 94.6%, and 99.1% for M1, M2, and M3, respectively, following pseudo-first-order kinetics. The free radical scavenging assays confirmed that hydroxyl radicals (•OH) were responsible for the RhB conversion.These results highlight the key influence of ZnO layer thickness and mass transfer on photocatalytic performance, de-monstrating the multifunctionality of ZnO-coated membranes, including efficient pollu-tant degradation and self-cleaning capability.

Abstract: Eleven resin cements, used as core build-up materials in this study, were evaluated via the following measurements: (a) push-out force between root dentin and fiber post; (b) pull-out force between core build-up material and fiber post; (c) shear bond strength of resin cement to root dentin; (d) flexural strength of resin cement; and (e) flexural modulus of elasticity of resin cement. All tests were performed at two time periods: after 1-day storage in water (Base) and after 20,000 thermocycles (TC 20k). For the push-out test, single-rooted human premolars were used to create simulated cavities. The specimens were sectioned horizontally perpendicular to their long axes into 2-mm slices. These slices were then subjected to push-out test to determine the bond strength between human root dentin, resin cement layer, and the fiber post. There were no significant differences in bond strength between Base and TC 20k. Therefore, surface pretreatments of multiple substrates with universal adhesives for fiber post cementation could ensure not only strong, but also durable, adhesion over time.

Abstract: The incorporation of recycled metallurgical slags into refractory materials constitutes a promising approach to enhancing sustainability in the refractory industry. This study investigates the effect of vanadium-bearing slag aggregates as partial replace-ments for tabular alumina in castables and compares their behaviour with high-alumina and bauxite-based castables. Two vanadium-bearing slags with differ-ent mineralogical compositions were introduced in the 1-3 mm aggregate fraction with substitution up to 25 wt.%. Their effects on microstructure, thermo-mechanical performance and corrosion resistance were evaluated. The introduction of vanadi-um-bearing slag significantly alters the microstructure of the castables, affecting their performance. Both slags displayed grains with higher porosity, microcracking, and heterogeneity compared with tabular alumina, but show similarities with bauxite grains. Slag 1, enriched in calcium aluminate phases, provides limited mechanical strength but improved corrosion resistance due to improved bonding with the matrix. Slag 2, containing a higher spinel content, enhances mechanical strength, showing behaviour comparable to bauxite-based castables, particularly at 10 wt.% replacement. Vanadium is mainly present in metallic form and as Mg(Al,V)2O4 spinel in both slags. Upon firing, vanadium migrates toward grain boundaries and reacts with surround-ing calcium aluminate phases to be incorporated in Ca(Al,V)2O4 and Ca(Al,V)4O7, while the spinel phase remains stable.

Abstract: Porous Ca₂Mg₂Al₂₈O46 (C₂M₂A₁₄) ceramics are highly competitive candidates in the field of critical metal filtration due to their attractive non-metallic inclusions removal capacity. However, the low mechanical strength and inadequate thermal shock resistance (TSR) of these materials restrict their further application. In this work, ZrO₂ toughened C₂M₂A₁₄-based porous ceramics are fabricated by using the polymer sponge replica method. Nano-sized ZrO₂ particles derived from nano-ZrO₂ sol are beneficial to enhance the mechanical properties and TSR of porous ceramics. The optimized porous C₂M₂A₁₄ ceramics exhibit robust compressive strength (2.15 MPa), good residual strength ratio (66.4%) and excellent filtration efficiency in the reduction of total oxygen content (68.4%) by adding 3 wt% ZrO₂ sol. These excellent comprehensive properties of as-prepared porous C₂M₂A₁₄ ceramics make it a potential alternative material for critical metal filtration.

Abstract: Concentrated solutions of polycarbosilane (PCS) are critically important for the development of continuous SiC precursor fibers, where solvent–polymer interactions govern rheology, viscoelastic stability, and spinnability. In this work, PCS solutions in two nonpolar hydrocarbon solvents with different molecular architectures as linear n-heptadecane and bicyclic decalin were systematically investigated over a wide concentration range, with emphasis on the semi-dilute entangled and concentrated regimes relevant to solution-based fiber spinning. A combined experimental approach involving steady and oscillatory rheometry and Fourier-transform infrared (FTIR) spectroscopy was used to elucidate the influence of solvent structure on solvation, viscoelastic response, microstructural organization, and local intermolecular interactions. Despite similar dilute-solution interaction parameters, the concentrated regimes exhibit pronounced solvent-dependent differences in elasticity, flow behavior. For the first time, linear heptadecane is identified as a viable and technologically promising solvent for PCS, enabling the formation of termostability homogeneous concentrated solutions with enhanced deformability. This behavior opens a realistic pathway toward a new solution-based fiber-spinning route based on elasticity-controlled processing. The results demonstrate that solvent molecular geometry governs the structure–rheology–processability relationship of concentrated PCS systems rather than solubility parameters alone, providing a new framework for solvent selection in SiC precursor fiber technologies.

Abstract: The utilization of slag-based materials as non-carbonated CaO sources has attracted increasing attention as a strategy to reduce limestone consumption and CO₂ emissions in cement manufacturing. However, compressive strength development in cementitious systems incorporating slag and CaCO₃ replacement is governed by complex interactions among slag chemistry, mixture design, and physical properties, which makes systematic interpretation and prediction challenging. In this study, a structured dataset was compiled from previously published experimental investigations on clinker and cement systems incorporating various slag types and CaCO₃ replacement levels. The dataset integrates slag chemical composition, mixture design parameters, and physical properties with compressive strength measured at 3 and 28 days. Based on observed experimental trends, compressive strength prediction at multiple curing ages was formulated as a multi-output regression problem to explicitly account for the correlated nature of strength development over time. The results reveal clear nonlinear relationships between compressive strength, curing age, and multiple material parameters. Mixed-slag systems generally exhibit higher early-age strength compared to single-slag systems at comparable CaCO₃ replacement levels, while differences among systems become less pronounced at later ages. These findings indicate that compressive strength at different curing ages is interrelated and influenced by shared material characteristics rather than independent variables. Overall, this study provides a data-driven analysis of strength development trends in slag-blended cementitious materials and establishes a consistent literature-based dataset framework suitable for multi-age strength modeling. The proposed approach offers a transparent basis for future predictive modeling and optimization of cement systems incorporating slag-based non-carbonated CaO sources.