Thanks to a considerable number of fascinating properties, titanium (Ti) and Ti alloys play important roles in a variety of industrial sectors. However, Ti and Ti alloys could not satisfy all ...industrial requirements; the degradation of Ti and Ti alloys always commences on their surfaces in service, which declines the performances of Ti workpieces. Therefore, with aim to further improve their mechanical, corrosion and biological properties, surface modification is often required for Ti and Ti alloys. This article reviews the technologies and recent developments of surface‐modification methods with respect to Ti and Ti alloys, including mechanical, physical, chemical, and biochemical technologies. Conventional methods have limited improvement in the properties and/or restriction on the geometry of workpieces. Therefore, many advanced surface‐modification technologies have emerged in recent decades. New methods make Ti and Ti alloys have better performance and extended applications. With requirement of high surface properties in future. Understanding the mechanism in various surface‐modification methods, combining the advantages of current technologies and developing new coating materials with high performance are required urgently. As such, incorporation of different surface‐modification technologies with high‐performance modified layers may be the mainstream of surface modifications for Ti and Ti alloys.
The technologies and recent development of surface‐modification methods for titanium (Ti) and Ti alloys are reviewed. Such technologies have expanded the applications of Ti and Ti alloys in the past and present due to their enhanced surface properties. Likewise, the mainstream of surface modifications for Ti and Ti alloys in the future is also discussed.
Wear and friction are two unavoidable failures in mechanical systems with moving components. Hence, the invention of new materials to curtail material losses and frictional energy remains a ...formidable obstacle in modern times. High entropy alloys (HEAs) introduce a revolutionary alloy design concept focused on several primary elements and vast compositional space. They offer considerable promise for the development of materials with exceptional wear resistance and reduced friction owing to their exceptional thermal stability, high hardness, good corrosion resistance, and superior mechanical strength. Therefore, researchers have shown a growing interest in HEAs over the last decade to obtain outstanding tribological properties that are unachievable with traditional alloys. This review focuses on various aspects of HEAs tribology such as alloying, heat treatment, surface alterations, coatings, and composites under dry and lubricated conditions. A critical assessment of the microstructure developments, manufacturing processes, and parametric variables that govern the tribo-behavior of HEAs also falls under the span of this review. Finally, this review not only highlights the major findings of the preceding research but also proposes future recommendations on the manufacturing and required advancement of HEAs for diverse tribological applications.
Cold plasma (CP) is an emerging technology, which has attracted the attention of scientists globally. It was originally developed for ameliorating the printing and adhesion properties of polymers ...plus a variety of usage domains in electronics. In the last decade, its applications were extended into the food industry as a powerful tool for non-thermal processing, with diverse forms for utilization.
This review presents an overview of recent studies on the application of cold plasma in the food industry. Specific areas discussed include microbial decontamination of food products, packaging material processing, functionality modification of food materials and dissipation of agrochemical residues. The application of CP has also been expanded into areas, such as hydrogenation of edible oils, mitigation of food allergy, inactivation of anti-nutritional factors, tailoring of seed germination performance and effluent management. In addition, the paper provides a summary of plasma chemistry and sources, factors influencing plasma efficiency and strategies for augmentation. Furthermore, key areas for future research are highlighted and salient drawbacks are discussed.
The recent studies conducted on the interaction of reactive species with food contact surfaces establish plasma processing as an eco-friendly technique with minimal changes to food products, making it a befitting alternative to traditional techniques. Active researches focused on up-scaling for commercial applications are urgently required.
•Cold plasma technology has continued to gain positive ratings in the food industry.•Interaction of reactive species with food materials minimally affects quality parameters.•New pathways for their utilization during food processing were highlighted.•Future research pathways to facilitate their recognition were proposed.
Sodium layered oxides NaxMO2 (x ≤ 1 and M = transition metal) are of great interest for sodium-ion batteries due to their high energy density and cost-effectiveness. However, these materials, whether ...they are stoichiometric (Na/M ≈ 1 as in O3 NaMO2) or not (Na/M ≈ 0.7 as in P3/P2 NaxMO2), have certain disadvantages, namely sensitivity to humidity or inadequate capacity, respectively. Herein, we propose an intermediate composition Na0.85Ni0.38Zn0.04Mn0.48Ti0.1O2 that we succeed to stabilize in either O3 or a nanoscale mixture of O3–P3 or O3–P2 phases as proven by X-ray diffraction and transmission electron microscopy, through complex synthesis approaches including quenching, slow cooling and annealing in different atmospheres (Ar, air, O2 etc). We rationalize the stabilization of different phases and microstructure as a function of synthesis conditions and show how it influences the electrochemical performance. Through this study we identified a single phase O3 Na0.85Ni0.38Zn0.04Mn0.48Ti0.1O2 synthesized at 1000 °C in air, which exhibits a high capacity of ∼170 mAh/g and good moisture stability. Furthermore, thanks to the synthesis-structure- electrochemical performance relationship identified here, we believe that this study will provide a reliable basis for optimizing the synthesis for best performing sodium layered oxides for commercialization.
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•Sodium layered oxides preferred as Na-ion cathode for their high capacity and energy.•Both O3 and P2 sodium layered oxides bear advantages and disadvantages.•Composition intermediate Na0.85Ni0.38Zn0.04Mn0.48Ti0.1O2 between O3 and P2 explored.•Synthesis conditions optimized to attain single phase O3 or O–P intergrowths.•Discussed key synthesis parameters to ensure homogeneity and cycling property.
Surface modification, which is simply about the end-capping of the reactive silanol groups located in silica wet gel to satisfy hydrophobic behavior, has great importance in the production of silica ...aerogels in ambient conditions. In this study, silica aerogels were synthesized with a sol-gel method via ambient pressure drying. A two-step surface modification was performed on wet gels by using various silanes with different contents (6%, 10% or 20% by vol in n-hexane) to control the extent of irreversible shrinkage during drying. Mono-functional (TMCS) and three-functional silanes (MTMS, MTES and MEMO) were selected for this purpose. The impact of the type and amount of the silylating agents on the microstructure, pore characteristics and hygroscopic nature of resulting aerogels were identified by conducting FTIR, SEM and BET analyses and contact angle measurements. According to characterization results, MTES exhibits a competitive performance compared to classically used TMCS, as the silica aerogels modified with 10% of MTES was obtained in a well-developed with mesoporous structure with very high specific surface area (SBET = 964m2/g) and high hydrophobicity (Θ = 137°). On the other hand, organically functionalized silane MEMO and MTMS, also display noteworthy results (monolithical structure with highly developed porous network and high degree of hydrophobicity) at the low contents (at 6% and 10%). These outcomes are crucial as they may encourage the future attempts on introducing three-functional silanes during surface modification, as these silanes yield high silylation performance and causes the synthesis of well-qualified silica aerogel in ambient conditions.
•B,Cs co-doped g-C3N4 nanosheets successfully were synthesized.•B,Cs co-doped g-C3N4 nanosheets showed H2 evolution rate of 1120 μmolg-1h−1.•The optimized structure showed H2O2 production rate of 113 ...μmolg-1h−1.•B and Cs doping increased charge carrier mobility in g-C3N4 structure.•Thin nanosheets decreased diffusion distance for the charge carriers and reactants.
This study reports the synthesis of a highly efficient visible-light-driven photocatalyst for hydrogen evolution and H2O2 production by manipulating the electronic band structure and surface properties of g-C3N4. Boron and caesium co-doped g-C3N4 porous and wrinkled nanosheets were nobly synthesized by using recrystallization of melamine in water in the presence of boric acid and CsCl followed by calcination and thermal etching. The prepared nanosheets showed an extremely porous and wrinkled structure with high surface area and edge sites. The optimized B, Cs co-doped g-C3N4 nanosheets exhibited a stable hydrogen evolution rate of 1,120 μmolg-1h−1 in the presence of triethanolamine, which is 7.7 times higher than that of the bulk. Moreover, this optimized structure showed a greatly increased hydrogen peroxide production rate of 113 μmolg-1h−1 compared to that (19 μmolg-1h−1) of the bulk GCN-B. Meanwhile, the optimized structure showed a high photooxidation ability toward RhB oxidation. This outstanding improvement in photocatalytic performance is attributed to the enhanced charge carrier mobility in the π-conjugated structure and increased accessible reaction sites for photocatalytic reactions originated from the synergetic effect of co-doping and formation of the porous and wrinkled nanosheets.
Since their first synthesis, carbon nanotubes (CNTs) gained remarkable research interest owing to their astonishing mechanical properties and extensive range of potential applications in various ...sectors, such as aerospace, automobile, biomedical, defence, energy, etc. This paper covers numerous characterization techniques, synthesis approaches and properties of the CNTs, reported by earlier researchers in the past. The technological and industrial needs for the development of lightweight nanocomposites have led to the significant advancements in the preparation of CNT-reinforced composites. In preliminary sections, the properties and applications of the CNT-reinforced nanocomposites are elaborated along with the issues related to their preparation. Here, various nanotubes synthesis processes, such as arc discharge, laser ablation and chemical vapour deposition, are exemplified with the support of published works. Furthermore, we have also addressed the several surface modification techniques of CNTs, such as purification, functionalization and dispersion, which make this review novel and exhaustive. In order to address the limitations and challenges incurred during the preparation of various CNT-reinforced polymer/metal matrix composites, an extensive collection of the published literature is reported and discussed, thoroughly. Based on this exhaustive review, some specific observations are made which would facilitate upcoming researches to explore the research opportunities in the preparation of CNTs and CNT-reinforced composites and their potential applications for the high-performance structures/components.
The interlayer assembled electrode modified with surface functionalized Ti3C2Cl2 MXene nanodots exhibit excellent pseudocapacitor storage performance (2010.8F g−1 at 1.0 A g−1, 94.1% capacity ...retention after 10,000 cycles).
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Although electrodes based on two dimensional hybrids with interstratification-assemble have been widely studied for supercapacitors, the performance enhancement still remains challenge mainly due to the random dispersion of surface passivated two dimensional nanosheets. Herein, a new covalent surface functionalization of MXene-based Ti3C2Cl2 nanodots-interspersed MXene@NiAl-layered double hydroxides (QD-Ti3C2Cl2@NiAl-LDHs) hybrid electrode with superior pseudocapacitor storage performance has been elaborately designed by electrostatic-assembled. As a result, the QD-Ti3C2Cl2@NiAl-LDHs electrode exhibits a super specific capacitance of 2010.8F g−1 at 1.0 A g−1 and high energy density of 100.5 Wh kg−1 at a power density of 299.8 W kg−1. In addition, 94.1% capacitance retention is achieved after cycling for 10,000 cycles at 1.0 A g−1, outperforming previously reported of two dimensional hybrids electrode for supercapacitor. Furthermore, density functional theory (DFT) calculations show that the superior pseudocapacitor storage performance of the QD-Ti3C2Cl2@NiAl-LDHs may be attributed to the creation of numerous electrochemical active sites and the enhancement of electrical conductivity by the QD-Ti3C2Cl2 MXene. This work provides new strategy for developing excellent pseudocapacitor supercapacitor based on two dimensional hybrid electrode.
In addition to its use as a lightweight material, pure magnesium is a promising candidate for prospective bioimplants considering its excellent biocompatible properties. Regardless of what Mg ...application is used, the ultimate goal is to improve magnesium's mechanical properties and degradation behaviour. Because of the high affinity for oxygen native oxide layer of gas-atomized powders is naturally formed in contact with the atmosphere. S/TEM investigation of the native oxide of the Mg powder particles revealed a nonhomogeneous nano-crystalline MgO layer. MgO is relatively soluble in water and does not provide sufficient corrosion protection. Among various surface treatment methods, conversion of the non-protective magnesium oxide to carbonate products is possible depending on the environmental conditions. This work used a simple experimental method using CO2 and water vapour to achieve surface carbonation of Mg powders. Two carbonated samples and pure magnesium were prepared by direct extrusion. The samples after carbonation retained good mechanical properties and the layer of carbonates had a significant impact on corrosion resistance. 1 day carbonation resulted in transformation of native oxide into amorphous layer and reduction of corrosion rate. Longer carbonation (10 days) revealed layer growth and transformation of native oxide to crystalline nesquehonite structure.
