REVIEWS ON ADVANCED MATERIALS SCIENCE

Abstract This review encompasses properties and applications of polycrystalline or amorphous, Transparent Conducting Oxides (TCO) semiconductors. Coexistence of electrical conductivity and optical transparency in TCO depends on the nature, number and atomic arrangements of metal cations in oxides, on the resident morphology and presence of intrinsic or introduced defects. Therefore, TCO semiconductors that are impurity-doped as well as the ternary compounds and multi-component oxides consisting of combinations are discussed. Expanding use of TCO is endangered by scarcity, cost of In, fragility of glass, limited transparency to visible light, instability above >200 °C, non-flexible for application of flexible solar cell; thus driving search for alternatives such as graphene or CNT, that are more stable under acidic, alkaline, oxidizing, reducing and elevated temperature. There are reasons to conclude that there is need to develop large area deposition techniques to produce TCO films with high deposition rate. TCOs are mostly n-type semiconductors, but p-type are also being researched

Abstract Nanotechnology allocate with the production and usage of material with nanoscale dimension, nanoparticles are large surface area to volume ratio and thus very specific properties. Zinc oxide (ZnO) nanoparticles had been in current studies due to its large bandwidth and high exciton binding energy and it has prospective applications such as electronic, optical, mechanical, magnetic and chemical properties that are significantly different from those of bulk counterpart. The aims of this review to provide a comprehensive view on structural, synthesis and electrochemical properties of the ZnO nanoparticles, which were synthesized by different methods.

Phosphating is the most widely used metal pretreatment process for the surface treatment and finishing of ferrous and non-ferrous metals. Due to its economy, speed of operation and ability to afford excellent corrosion resistance, wear resistance, adhesion and lubricative properties, it plays a significant role in the automobile, process and appliance industries. Though the process was initially developed as a simple method of preventing corrosion, the changing end uses of phosphated articles have forced the modification of the existing processes and development of innovative methods to substitute the conventional ones. To keep pace with the rapid changing need of the finishing systems, numerous modifications have been put forth in their development - both in the processing sequence as well as in the phosphating formulations. This review addresses the various aspects of phosphating in detail. In spite of the numerous modifications put forth on the deposition technologies to achieve different types of coatings and desirable properties such as improved corrosion resistance, wear resistance, etc., phosphate conversion coating still plays a vital part in the automobile, process and appliance industries.

Abstract Geopolymers are green materials with three-dimensional silicon and aluminum tetrahedral structures that can be serving as environmentally friendly construction materials and therefore have the potential to contribute to sustainable development. In this paper, the mechanism and research progress regarding the carbonation resistance, structural fire resistance, corrosion resistance, permeation properties and frost resistance of geopolymer concretes are reviewed, and the main problems with the durability of geopolymer concretes are discussed. Geopolymers possess the superb mechanic property and their compression strengths could be higher than 100 MPa. Generally, the higher the GPC strength, the better the carbonation-resistant. GPC has excellent fire resistance, due to geopolymers are acquired an inorganic skeleton which is affected by the alkali content, alkali cation, and Si/Ai ratio. There are a large number of Al-O and Si-O structures in geopolymers. Geopolymers do not react with acids at room temperature and can be used to make acid-resistant materials. Besides, GPC owning low porosity volume shows good resistance to permeability. The freezing-thawing failure mechanism of geopolymer concretes is mainly based on hydrostatic and osmotic pressure theory. GPC has poor frost resistance, and the freezing-thawing limit is less than 75 times.

Abstract The crystal structures of various types of perovskite halide compounds were summarized and described. Atomic arrangements of these perovskite compounds can be investigated by X-ray diffraction and transmission electron microscopy. Based on the structural models of basic perovskite halides, X-ray and electron diffractions were calculated and discussed to compare with the experimental data. Other halides such as elemental substituted or cation ordered double perovskite compounds were also described. In addition to the ordinary 3-dimensional perovskites, low dimensional perovskites with 2-, 1-, or 0-dimensionalities were summarized. The structural stabilities of the perovskite halides could be investigated computing the tolerance and octahedral factors, which can be useful for the guideline of elemental substitution to improve the structures and properties, and several low toxic halides were proposed. For the device conformation, highly crystalline-orientated grains and dendritic structures can be formed and affected the photo-voltaic properties. The actual crystal structures of perovskite halides in the thin film configuration were studied by Rietveld analysis optimizing the atomic coordinates and occupancies with low residual factors. These results are useful for structure analysis of perovskite halide crystals, which are expected to be next-generation solar cell materials.

Abstract For low-carbon sustainability, recycled rubber particles (RPs) and recycled aggregate (RA) could be used to make rubber-modified recycled aggregate concrete (RRAC). The characteristics (compressive strength and peak strain) of RRAC with various amounts of RA and RPs after heating at various temperatures were studied in this work. The results show that high temperatures significantly decreased the uniaxial compressive strength (UCS), whereas the addition of RA (e.g., 50%) and RPs (e.g., 5%) can mitigate the negative effect caused by high temperatures. The peak strain can also be improved by increasing the replacement ratios of RA and RP. Support vector regression (SVR) models were trained using a total of 120 groups of UCS and peak strain experimental datasets, and an SVR-based multi-objective optimization model was proposed. The excellent correlation coefficients (0.9772 for UCS and 0.9412 for peak strain) found to illustrate the remarkable accuracy of the SVR models. The Pareto fronts of a tri-objective mixture optimization design (UCS, strain, and cost) were successfully generated as the decision reference at varying temperature conditions. A sensitivity analysis was performed to rank the importance of the input variables where temperature was found as the most important one. In addition, the replacement ratio of RA is more important compared with that of the RP for both the UCS and strain datasets. Among the mechanical properties of concrete, compressive strength and peak strain are two key properties. This study provides guidance for the study of RRAC constitutive models under high temperatures.

Abstract Considerable attention has been given to graphene as a reinforcement material for metal matrix composite (MMC) because of its great potential for use in the automotive and aerospace industry. In general, the difficulty in achieving optimally improved properties can be attributed to poor wettability, agglomerations, and non-uniform distribution of reinforcement in the MMCs. Therefore, in terms of structural integrity, interfacial bonding, and its strengthening mechanism are important to achieve a high performance composite, which makes it imperative to discuss the integration of graphene into the alloy. The reinforcement mechanism of graphene-reinforced aluminium alloy has been evaluated in a limited number of studies, and this article examines current publications in this area. This article outlines three key topics related to the key challenges of graphene as a reinforcement material, the strengthening mechanism of graphene in a metal matrix, and the factors limiting the properties enhancement. Lastly, future works and recommendations addressed are summarized. The review presented aims to benefit to a wide range of industries and researchers and serve as a resource for future scholars.

Abstract In this study, the authors have reviewed recent advances on the transient liquid phase (TLP) bonding technology for various applications especially power module packaging in view of the recent increasing demand for the production of vehicles, smartphones, semiconductor devices etc. TLP bonding is one of the potential technologies from clean technology that can replace the Pb-base solder technology without causing any serious environmental issues. It is based on the concept of both brazing as well as diffusion bonding. During TLP bonding, the liquid phase is transiently formed at the bonding interface. At this point, the melting point of filler metal increases due to the diffusion of element which degrades the melting point from liquid phase to base metal. Subsequently, the bonding occurs by isothermal solidification at the bonding temperature of liquid phase. Here, after bonding, the melting temperature of the joint layer becomes higher than bonding temperature. This review introduces the various aspects of TLP bonding including its principle, materials, applications, advantages and properties in detail.

Abstract Cellulose nanocrystals (CNC) are a class of nanoscale biopolymers produced from cellulose sources. CNC materials have gained growing interests which can be attributed to their excellent properties such as excellent biocompatibility, good mechanical properties and high aspect ratio whilst also being an inexpensive material that can be produced from green and renewable sources. Due to the abundant hydroxyl functional groups, the surface of CNC materials are ready to be tuned and functionalized via chemical reactions allowing for many different applications, such as being a reinforcing agent to be incorporated into a hydrophobic polymer matrix. In this review paper,we firstly introduce the general methods for producing CNC from different sources. Different strategies used for surface modification ofCNCare then discussed. Finally, the recent progress on the applications of CNC and CNC composite materials are described in detail.

Abstract Cellulose nanomaterials (CNMs) naturally exist in biomass. Recent developments in nanotechnology and extraction procedure of CNMs open up a new era in the polymer composites industry. Abundant, renewable, biodegradable, transparent, light weight, and most importantly, low cost make CNMs the ideal material for packaging, automotive, construction, and infrastructure applications. CNMs are generally used as materials for polymer matrix reinforcement in the composites industry. The industrial-scale manufacturing of CNM/thermoplastic composites remains an unsolved puzzle for both academics and industries. The dispersion of nanocellulose in polymer matrix is the central problem inhibiting the manufacturing of CNM/polymer composites at an industrial scale. Several attempts were made to disperse nanocellulose effectively in a polymer matrix and improve compatibility between the matrix and CNMs. Chemical-aided surface modification of CNMs has been effective in several cases; however, chemical toxicity, high price, and critical control of reactions make them unsuitable. This current review paper focuses on novel eco-friendly physical dispersion techniques of CNMs and their future scope of research. The physical dispersion techniques such as plasma-induced surface modification, ultrasonication, magnetic and electric field discharge, electrospinning, or drawing can visibly improve the dispersion state of CNMs. But several factors affect physical techniques’ performance, e.g. CNM type and forms, process conditions and parameters, etc. Moreover, the material-related factors interplay with the process-related factors. This review addresses the current state of knowledge on the physical dispersion techniques for CNMs and identifies challenges that are critical to adoption of these novel materials at commercial scale for future applications.

Abstract In this study, both individual and hybrid effects of industrial wastes (silica fume, fly ash), fibers (glass and basalt) and nanoparticles (nano SiO 2 , nanoclay) mixed with clay at different ratios were investigated in detail at macro and micro levels at different water contents and curing times. The efficiency of stabilization in clay soils was determined using Gray Correlation Analysis (GCA). A predictive model for the stress-strain relationship of stabilized soils with hybrid material was proposed. Results showed negligible changes in dry density and optimum moisture content with silica fume and fly ash, while nano SiO 2 and nanoclay induced significant variations. The unconfined compressive strength (UCS) tests showed a significant increase in soil strength with the addition of nanomaterials, especially after long curing times. The presence of nano SiO 2 and nanoclay in the composite specimens increased the UCS by 87.15 % and 63.83 % before curing, respectively, while it increased to 317.50 % and 219.74 % after the maximum curing time. GCA identified curing time as the most influential factor, followed by silica fume, glass fiber, and nanoclay, due to progressive bonding development. Nanoclay demonstrated superior UCS enhancement compared to nano SiO 2 , underscoring its effectiveness in soil stabilization. The study contributes to the literature to realize the full benefits of these additives to improve soil stability and the UCS performance, and to address waste recycling, increase the strength of subgrade soils under different environmental conditions, and reduce the costs associated with the use of waste.

Abstract The growing demand for lightweight, durable, and sustainable materials in the aerospace sector motivates the development of high value biocomposites. This work experimentally investigates the potential of pure bast flax fiber reinforced with zirconium dioxide (ZrO 2 ) nanoparticles at varying concentrations (1, 2, and 3 wt%) for light weight helicopter structures. Laminates were fabricated using a hand lay-up compression molding technique and characterized for low-velocity impact resistance, flexural strength, and interlaminar shear strength (ILSS). Further, scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) were used to characterize the thermo-mechanical performance and failure mechanisms. The key finding is that the 3 wt% ZrO 2 nanocomposite significantly enhanced all critical properties, it demonstrated a 63 % higher maximum impact force (740 N), a 86 % increase in flexural strength, reaching 134 MPa, compared to the 72 MPa pure flax, increased ILSS by 38.2 %, reaching 4.7 MPa, and a 91 % enhancement in the DMA storage modulus (8.46 GPa). These findings demonstrate the strong potential of these nanocomposites for use in demanding, weight-sensitive applications, such as lighter helicopter structures.

Abstract This study investigates the compression behavior of circular concrete columns confined with basalt fiber-reinforced polymer (BFRP) stirrups, comparing their performance with traditional steel-reinforced columns. The objective of the study is to assess the impact of the BFRP transverse reinforcements and concrete mix design (CMD) codes on the compressive strength (CS), energy accumulation (G Acc ), fracture energy (G F ), and ductility of RC cylinders. A total of 81 reinforced concrete (RC) cylinders were prepared using three distinct CMD codes and tested under axial compression. The specimens were confined with 6 mm and 8 mm BFRP and steel spirals/ties at varying rib spacings (45 mm, 60 mm, and 90 mm). The experimental results revealed that closer BFRP spiral/tie spacings (45 mm) significantly enhanced the CS by 7–15 % and G Acc by up to 59 % of the columns due to improved confinement effect, compared to those with larger spacings (60 mm and 90 mm). BFRP ties demonstrated superior performance in terms of CS, G Acc , and G F compared to BFRP spirals, particularly at moderate and larger spacings. Finite element model (FEM) simulations validated the experimental results with less than 8 % deviation and demonstrate a high degree of correlation between predicted and observed failure behaviors. The study suggests that BFRP spirals/ties reinforcements with optimal spacing can effectively replace steel in structural applications, offering comparable performance in strength, ductility, and energy absorption. These findings encourage the use of BFRP-based reinforcements in durable, lightweight, and eco-friendly concrete constructions.

Abstract The inherent brittleness and high-temperature recrystallization tendency of tungsten heavy alloys (WHAs) make balancing high strength and ductility under harsh conditions a major challenge. This study introduces V, Ta, and Re as strengthening elements into W-Ni-Fe-Co alloys by powder metallurgy, producing five alloy compositions (in weight fraction): the baseline sample S1 (W-2.46Ni-1.05Fe-0.7Co), single-doped samples S2 (1V), S3 (2Re), S4 (4Ta), and multi-doped sample S5 (1V-2Re-4Ta). The results show that S1 has the highest density of 98.6 ± 0.61 %; S3 has a peak hardness of 443.27 ± 13.33 HV; and S5 exhibits the best tensile strength and elongation, at 816.35 MPa and 8.92 %, respectively. These performance improvements are attributed to specific strengthening mechanisms: V enhances hardness and ductility through solid solution strengthening in the tungsten lattice and induces lattice distortion; Re promotes grain refinement and the formation of ReW phases, mainly enhancing hardness through grain boundary pinning; and Ta contributes to strength improvement by enriching and achieving second phase strengthening. In S5, the synergistic effect of multi-element doping effectively balances the heterogeneity of grain size and the distribution of the binder phase network, minimizing micropores and optimizing interface bonding, thereby achieving an excellent synergy between strength and ductility and expanding the alloy’s application potential.

Abstract The need for energy efficiency and sustainable building materials is increasing today. In this context, new material integrations that aim to improve the thermal and mechanical performance of building elements are being investigated. This study experimentally investigated the effects of two phase change materials (PCM-1(CACI 2 .6H 2 O), PCM-2(NEXTEK24D)) and a thermal insulation material (polyurethane) on the thermal conductivity and compressive strength of hollow bricks. The internal voids of the bricks were filled with polyurethane and two different PCMs to evaluate the contributions of these additives to the mechanical and thermal behavior of the building elements. The findings indicate that adding PCM increases the bricks’ thermal resistance values and reduces internal temperature fluctuations. Bricks filled with polyurethane and FDM showed increased compressive strength, up to 28 % vertically and 74 % horizontally, compared to reference specimens. This emonstrates that filling bricks with such materials improves their compressive strength and thermal insulation. In conclusion, bricks with PCM and polyurethane additives offer significant potential for energy-efficient building solutions, particularly in terms of thermal comfort and insulation. However, given the impact of these additions on mechanical performance, further research is needed to optimize material ratios and enhance applicability without compromising structural safety.

Abstract Polystyrene (PS) and its nanocomposites have shown considerable potential as selective barriers for gas permeation, yet the influence of molecular weight (MW) on their gas transport behavior remains insufficiently understood. In this study, three PS samples with ascending MWs (PS1–PS3) and their reduced graphene oxide (rGO) nanocomposites (PS1-G–PS3-G) were prepared via hot pressing. Notably, the water vapor transmission rate (WVTR) exhibited a non-monotonic dependence on MW, increasing from 1.50 g/m 2 ·day (PS1) to 1.59 g/m 2 ·day (PS2), then decreasing to 1.27 g/m 2 ·day (PS3). A similar trend was observed in the nanocomposites, which displayed lower WVTR values (0.54, 0.61, and 0.48 g/m 2 ·day, respectively). In contrast, the oxygen transmission rate (OTR) rose sharply with MW – from 509.41 g/m 2 ·day (PS1) to 1,119.8 g/m 2 ·day (PS2) and further to 4,586.11 g/m 2 ·day (PS3) – while rGO incorporation substantially suppressed oxygen permeability (40.72, 58.09, and 138.32 g/m 2 ·day, respectively). Hydrogen transmission rates (HTR) varied only slightly among the PS samples (830, 842, and 907 cm 2 /(m 2 ·day·0.1 MPa), and the addition of rGO induced minimal changes. Among all samples, PS1 and PS1-G exhibited the most favorable barrier selectivity, combining strong water and oxygen resistance with retained hydrogen permeability. These results demonstrate that MW plays a decisive role in governing gas barrier selectivity and provide design insights for optimizing polymer nanocomposites in advanced barrier applications.

Abstract Warm mix asphalt (WMA) is a sustainable innovation in road construction that enables bituminous mixtures to be produced and compacted at lower temperatures than traditional hot mix asphalt (HMA). This reduction in temperature significantly decreases greenhouse gas (GHG) emissions and other pollutants, supporting global climate change mitigation efforts. WMA technology enhances energy efficiency while maintaining the performance and durability of road surfaces, offering an environmentally responsible alternative for the construction industry. Its adoption reflects a commitment to reducing the carbon footprint of infrastructure projects. These innovations are anchored in three primary techniques, chemical additives, organic additives, and foaming processes, each of which contributes uniquely to reducing energy consumption while improving pavement performance. Extensive research has revealed the multifaceted advantages of WMA. Mechanically, WMA demonstrates exceptional properties, including enhanced resistance to stripping, fatigue, thermal cracking, and rutting, which collectively contribute to the longevity and resilience of asphalt pavements. Environmentally, the reduced energy demands of WMA production not only reduce emissions but also provide an opportunity to integrate recycled materials and industrial byproducts, further reinforcing its eco-friendly credentials. Economically, the lower production temperatures translate into operational cost savings, although a detailed analysis of long-term cost implications is essential to fully understand its financial viability. This review highlights the historical development, material innovations, and advanced techniques underpinning WMA, providing a thorough evaluation of its rheological and fractured properties. This research aims to support the widespread implementation of WMA in pavement applications. This study also emphasized the critical role of life cycle assessment (LCA) in quantifying the sustainability benefits of WMA mixtures. Moreover, the study explores the emerging trends and challenges in the widespread adoption of WMA, emphasizing the need for robust evaluations of its economic, environmental, and safety aspects. Ultimately, WMA technologies represent a pivotal innovation, offering an integrative solution to modernize the road construction industry while addressing pressing environmental concerns.

Abstract This research explores the synthesis of zinc oxide nanomaterials (ZnO NMs) through the utilization of neem leaf extract, presenting an environmentally conscious and sustainable methodology. The biosynthesized ZnO NMs exhibit dual functionality, showing remarkable efficacy in the photocatalytic degradation of natural organic matter (NOM) as well as antimicrobial activity against drug-resistant microorganisms. Under low-energy UV light, ZnO effectively degraded 92 % of NOM within a span of 180 min, concurrently exhibiting substantial antimicrobial effects against Escherichia coli and Candida albicans , characterized by significant inhibition zones. The research further highlights the application of low-energy UV light to improve the photocatalytic efficiency of ZnO NMs, thereby promoting sustainability and reducing the toxicity of by-products. The characterization of ZnO NMs was conducted employing various techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV–vis), and scanning electron microscopy (SEM). At a concentration of 3 g/l, ZnO accomplished a 92 % reduction in NOM over a period of 180 min, accompanied by a 59 % reduction in organic carbon deposition (OCD). The low levels presence of OCD on the surface after the reaction further confirmed the effectiveness of the process. The findings highlight the promise of neem-extract ZnO NMs as an eco-friendly and adaptable substance for environmental cleanup and antimicrobial uses, demonstrating significant antibacterial efficacy at concentrations of 0.05 mg/ml and 0.1 mg/ml.

Abstract The use of recycled tire rubber, particularly crumb rubber (CR), as a partial fine aggregate replacement offers a sustainable pathway to reduce environmental waste and conserve natural resources, aligning with SDG 9 and SDG 12. This review synthesizes 84 peer-reviewed studies to evaluate the mechanical performance, durability, microstructural characteristics, and practical applicability of crumb rubber concrete (CRC). While CRC typically shows reductions in compressive, tensile, and flexural strengths, stemming from weak ITZ bonding, low stiffness, and increased porosity. It exhibits improved ductility, freeze–thaw resistance, and chemical durability. Empirical polynomial regression models are introduced to quantify strength degradation as a function of CR content, and benchmarking against major design codes indicates that CR levels up to 20 % can satisfy minimum strength requirements for selected exposure classes. Recent enhancement strategies, including RF-RC systems and matrix modifications using sulfate-resistant cement, silica fume, and fly ash, demonstrate quantifiable gains, such as ∼25 % increases in compressive strength, post-crack residual strength improvements from 0.10 MPa to 1.4–3.1 MPa, and ductility enhancements exceeding 70 %. Environmental assessments further show that CRC and multi-waste composite systems can reduce embodied energy by 153–227 MJ/m 3 and CO 2 emissions by 30–135 kg/m 3 , with LCA studies reporting up to 75 % decreases in total environmental impacts. Field-scale investigations confirm CRC’s feasibility, with composite slabs achieving 10–19 % higher peak loads and 17–33 % higher first-crack loads than conventional concrete. Overall, limiting CR content to 10–20 % and employing performance-based mix optimization are recommended to balance mechanical performance, durability, and sustainability in next-generation low-carbon construction.

Abstract This narrative review explores the role of Artificial Intelligence (AI) in advancing the synthesis, optimization, and clinical translation of dental biomaterials. It critically evaluates how AI-driven approaches address existing challenges related to material performance, biocompatibility, and durability, while identifying current research gaps and outlining future perspectives. A comprehensive literature synthesis was conducted through electronic searches in PubMed, Scopus, Web of Science, and Google Scholar. Selected articles encompassed both experimental and computational studies. Case studies were analyzed to illustrate the application of AI techniques, including machine learning (ML) for predicting mechanical properties, deep learning (DL) for microstructural and imaging analysis, and optimization algorithms ( e.g. , genetic algorithms) for materials discovery and formulation enhancement. The findings indicate that ML models can accurately predict mechanical properties ( e.g. , flexural modulus), DL enables automated detection of material degradation, and optimization algorithms accelerate the discovery of advanced biomaterials such as high-entropy ceramics. AI also facilitates the development of personalized, adaptive materials, including pH-responsive and self-healing resin composites. Nonetheless, barriers remain, including data scarcity, limited generalizability, high computational demands, and lack of standardization. AI is poised to redefine the landscape of dental biomaterials by enabling smarter material design, improved performance prediction, and accelerated clinical translation. This review advances the field by integrating emerging computational approaches with practical needs and identifying unresolved challenges that hinder real-world adoption. Ultimately, leveraging AI alongside technologies such as 3D printing and digital twin systems can drive the development of next-generation biomaterials tailored to patient-specific clinical outcomes.