Search

This work presents the fabrication of a photocatalytic hydrogel band through facile one-pot processes of mixing with TiO2 nanotubes (TiNT)/graphene oxide sheets (GO)/polyvinyl alcohol (PVA), in situ photoreduction of GO and freeze–thaw gelation. The interactions between TiNT/rGO/PVA make the constructed porous gel network possess good mechanical strength with flexibility and self-healing capability. The gelation matrix also allows the TiNT/rGO/PVA hydrogel band to easily adhere to various smooth surfaces. The structural and optical analysis of the TiNT/rGO/PVA hydrogel bands indicated that the binding of rGO on TiNT can boost the photocatalytic activity by accelerating charge separation and inhibiting charge recombination of TiO2. Due to the combined effects of enhanced activity, porous features to facilitate molecular diffusion, and improved mechanical strength, the TiNT/rGO/PVA hydrogel bands exhibited excellent photocatalytic performance for the decomposition of dyes with well-maintained activity without a loss after repeated usages. These results showed the potential of hydrogel-based photocatalytic systems for more convenient and reliable usages in environmental remediation. [ABSTRACT FROM AUTHOR]

Due to the unique properties of titanium (Ti) and its alloys, it has a particularly wide range of applications in aerospace, automotive, medical and other fields. However, the problems of low surface hardness, high friction coefficient and low wear resistance of Ti alloys limit its development to a certain extent. The destruction of Ti and its alloys often occurs on the surface of materials such as wear damage, corrosion, and oxidation resistance. Therefore, the exploration and application of surface strengthening technology is particularly important. The cathodic plasma electrolytic deposition (CPED) technology, as a surface modification technology, can achieve better adhesion and facilitate the material to achieve better comprehensive performance. This paper briefly introduces the basic concepts, principles and development progress of CPED. Starting from the preparation of ceramic coatings, metal coatings, diamond-like carbon films and composite coatings, it summarizes the application of CPED in Ti and its alloys. Applications in alloys to improve thermal oxidation resistance, wear resistance, corrosion resistance, and film-based adhesion. At the end, its development in the new era environment is prospected. [ABSTRACT FROM AUTHOR]

Water pollution is a serious problem in both developed and developing countries. Several methods have been used to purify wastewater, among which photocatalytic decomposition is widely used to purify organic pollutants in wastewater. In this work, hollow nanospheres of titanium dioxide TiO2 were first prepared by the carbon sphere template method and sol–gel method, and then, the hollow nanospheres of titanium dioxide (TiO2) were compounded with silicon dioxide (SiO2) by the impregnation method to generate complexes with different ratios of hollow nanoparticles of titanium dioxide and silicon dioxide. The best degradation performance of the h-TiO2/SiO2 photocatalytic materials was achieved when the ratio of h-TiO2 to SiO2 used was 5:1. The cyclic decomposition efficiency of the 5:1 h-TiO2/SiO2 composites showed only a slight change in the photocatalytic capacity compared to the first cycle, thus ensuring the durability of the samples. However, quenching experiments yielded that hydroxyl radicals play a major role in the degradation process, and possible reaction mechanisms are discussed in detail. The high photocatalytic performance of the environmentally friendly h-TiO2/SiO2 nanosphere photocatalysts makes them ideal for water purification applications and offers potential applications for the utilization of solar energy to effectively reduce environmental pollution. The h-TiO2/SiO2 nanophotocatalysts can not only degrade dyes but can also be valuable for self-cleaning glass applications. [ABSTRACT FROM AUTHOR]

Water-induced mechanically adaptive rubber nanocomposites were prepared by mixing bacterial cellulose whiskers (BCWs) suspension with carboxylated acerlonitrilebutadiene rubber (XNBR) latex, followed by latex blending method. The introduction of BCWs into XNBR enhanced the tensile storage modulus (F) significantly, which originated from the formation of a rigid 3D filler network within matrix as well as the interfacial interaction between filler and matrix. The water uptake ratio of nanocomposite films increased with BCWs content, from 5.5% for neat XNBR to 54% for nanocomposite with 20 phr (parts per hundred rubber) BCWs. Upon submersed in water, the nanocomposite films showed dramatic decrease in E', especially for which filled with high BCWs loadings. For example, E of nanocomposite with 20 phr BCWs was decreased by 98.04% after equilibrium swelling compared with only 52.02% for nanocomposite with 3 phr BCWs. The remarkable watertriggered modulus changes are attributed to the disentanglement of BCWs network after swelling. The prepared XNBR-BCWs nanocomposites with mechanically adaptive properties could contribute to develop the new type of rubber-based smart materials. POLYM. ENG. SCI., 59:58-65, 2019., INTRODUCTION Functional polymer nanocomposites which associate desirable nanofiller with polymer matrix and possess a broad range of properties (e.g., mechanics, electricity, thermology, and impermeability) have been devoted into academia and [...]

In this work, graphene oxide (GO) with various oxidation degrees were synthesized by adjusting the dosage of oxidation agent based on a modified Hummers' method, and were then used for the fabrication of the styrene-butadiene rubber (SBR)/GO nanocomposites through latex coagulation method, followed by a high-temperature cure process. The vulcanization characteristics, thermal stability, mechanical properties, thermal conductivity as well as solvent resistance of SBR/GO nanocomposites were investigated. The results indicated that various surface structures of GO due to oxidation degrees may lead to different dispersion states of GO in the rubber matrix, and thus greatly influenced the cure rate, mechanical properties as well as thermal conductivity of SBR/GO nanocomposites. The optimal (moderate) oxidation degree of GO was achieved at the oxidation agent (KMn[O.sub.4])/graphite weight ratio 9/5, for which case the tensile strength, tear strength, and thermal conductivity of SBR/GO nanocomposites increased by 271.3%, 112.3%, and 28.6%, respectively, compared with those of neat SBR. In addition, the mentioned nanocomposites also showed the best solvent resistance in toluene. POLYM. ENG. SCI., 58:1409-1418, 2018. [C] 2017 Society of Plastics Engineers, INTRODUCTION As the most widely used synthetic rubber, styrene-butadiene rubber (SBR) has been applied in tire tread, adhesive tape, rubber hose, medical equipment, and so forth. [1] To satisfy the [...]

Abstract: Clostridium difficile, the etiological agent of Clostridium difficile infection (CDI), is a gram-positive, sporeforming bacillus that is responsible for ~20% of antibiotic-related cases of diarrhea and nearly all cases [...]

Modification of fillers and enhancement of the dispersion and compatibility of fillers in a rubber matrix is an effective way to improve the comprehensive performance of rubber. In this work, graphene oxide (GO) was modified with each of polyvinylpyrrolidone, 1‐allyl‐3‐methylimidazole hydrochloride and 1‐butyl‐3‐methylimidazole hexafluorophosphate. Then, modified GO/natural rubber (NR) composites were fabricated using a latex‐mixing method. By combining experiments and molecular simulation, we investigated the relationship between the microstructures and properties of the modified GO/NR composites. Results showed that the polyvinylpyrrolidone‐modified GO/NR composite had the smallest fractional free volume and mean square displacement, which led to excellent solvent resistance, and dynamic and physical mechanical properties. This study provides new insights into the design of high‐performance GO/NR composites at the molecular level. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]