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Abstract: The accelerated ultraviolet aging behavior of poly(1,3,4-oxadiazole) fibers (POD fibers) exposed to artificial environment for different durations were studied. The influence of ultraviolet light on the intrinsic viscosity, structure, appearance and morphology, mechanical properties of POD fibers were investigated during aging by ATR-FTIR and UV-spectra, XPS, WXRD, SEM and tensile strength tester. The results revealed that the structure and properties of POD fibers were affected by UV light. Tensile strength and breaking elongation of POD fibers were severely decreased after 48h UV light irradiation, and the change of intrinsic viscosity indicated that only degradation but not crosslink occurred. Disruption of oxadiazole rings and formation of carbonyl and amide were observed. UV aging process in nitrogen atmosphere suggested that the oxygen was indispensable and the essence of POD UV aging was photo-oxidation process. POD was amorphous and the recrystallization on surface was present after UV aging due to degradation. Morphology of POD fiber surface was damaged after UV aging. [ABSTRACT FROM AUTHOR]

Abstract: A series of olivine LiFe1−xCoxPO4/C (x=0, 0.005, 0.01, 0.015, 0.02 and 0.025) nanoplates were synthesized by a facile solvothermal synthesis combined with esterification reaction. The structure, morphology and electrochemical performance of the samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatic intermittent titration technique (GITT), galvanostatic charge/discharge tests and electrochemical impedance spectroscopy (EIS). Based on the first-principle density functional theory (DFT), the diffusion energy barriers of Li ions for LiFe1−xCoxPO4 (x=0–0.025) were also calculated to further investigate the influence of doping Co on LiFePO4/C cathode material. The results showed that the prepared nanoplates with a very thin thickness along b-axis grow preferentially along the [001] direction of (101) lattice planes, which can minish the distance of Li+ ion diffusion along the [010] direction. The calculated results suggested that the LiFe0.99Co0.01PO4/C had a lowest lithium ion diffusion energy barrier, accordingly possessing a highest lithium ion diffusion coefficient. The electrochemical performance was improved by doping an appropriate amount of Co, and it might be attributed to the fact that the doped Co ion can enhance exchange current density and lithium ion diffusion coefficient. Among all the doped samples, LiFe0.99Co0.01PO4/C exhibited the best rate capability and cycling stability, with the initial discharge capacity of 154.5mAhg−1 at 0.5C. Remarkably, it still showed a high discharge capacity of over 96.9mAhg−1 and good cycle retention even at a high rate of 10C. [Copyright &y& Elsevier]

An investigation of the solubility and loading ability (LA) of nine benzene derivative drugs with different chemical structures onto viscose substrate in supercritical carbon dioxide fluid (SCF–CO 2) was performed, in order to construct some bases at the first time for manufacturing drug-loaded cosmetic textiles by employing an ecofriendly, sustainable supercritical methodology. Moreover, a release behavior of each of the loaded drugs from viscose substrate in a solvent of ethanol was also disclosed. The results show that a more hydrophobicity of the substituent group linked on the benzene ring readily led to a higher solubility in SCF-CO2, while an overlong aliphatic tail and its molar mass also brought some effects on its dissolving behavior. As for the isomer drugs, the locations of a methoxy group (-O-CH 3) at the ortho-position to the carboxyl group (-(C O)–OH) in the benzene ring resulted in the highest solubility, while a para-position showed the lowest solubility in SCF-CO 2. The loading ability (LA) for most of the tested drugs mainly depended on their solubilities in SCF-CO 2 , and was also affected by the interactions between the drug and viscose substrate. The investigation of drug release reveals that the LA played a predominant role in the release behaviors of the tested drugs with different substituent groups, molar mass or aliphatic chains and isomer structures. Moreover, the drug molecular size and its interaction with viscose substrate also presented effects on the subsequent release behaviors in the utilized release system and conditions. Image 1 • Basises for ecofriendly manufacturing drug-loaded cosmetic textiles were developed in SCF-CO 2. • Different dissolving and loading abilities of nine drugs on viscose in SCF-CO 2 were explored. • Hydrophobicity and position of a substituent group brought effect on drug dissolving behavior in SCF-CO2. • Loading ability mainly depended on drug solubility in SCF-CO2, then the interactions with substrate. • Release behavior was notably influenced by drug loading ability, then molecular size and interactions with viscose. [ABSTRACT FROM AUTHOR]

A new kind of anti-dripping polyethylene terephthalate (PET) fabric was successfully prepared by simultaneous gamma radiation-induced grafting polymerization of glycidyl methacrylate (GMA) and divinylbenzene (DVB) onto the surface of PET fabrics. The grafting yield (GY) and anti-dripping effect were optimized by changing the total absorbed dose, dose rate, concentration and the feed ratio of GMA and DVB. The grafting yield increased with the increase of absorbed dose and GMA monomer concentration, and decreased with the dose rate. It is confirmed that PET fabrics had been modified by Fourier transform infrared spectroscopy analysis. The tensile strength and elongation at break of modified PET fabrics were improved compared with original PET fabrics. The limiting oxygen index (LOI) of modified PET fabrics with the GY of 23–25% was 21.5, which was similar to that of unmodified PET fabrics. However, the anti-dripping performance of PET fabrics was improved remarkably after radiation modification due to the crosslinking of the sidechains grafted on the PET surface. This anti-dripping fabric may be promising for fire protective clothing. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates in detail the effects of processing parameters (pressure and temperature) on the internal structure and interfacial compatibility of unidirectional (UD) sheets of ultrahigh molecular weight polyethylene (UHMWPE) fiber/styrene–ethylene–butylene–styrene (SEBS) resin composites by dynamic mechanical thermal analysis (DMTA) and T-peel tests. The variation of storage moduli of the composites with the processing pressure indicate that almost all of the resin phase had changed into the interfacial phase; the tan δ curves also testified that the ethylene–butylene (EB) segment of SEBS matrix was entangled with the molecular chains of polyethylene (PE) fibers. Moreover, the result of the T-peel tests of composites indicated that the pressure produces more significant changes than the temperature for both monofilm and no-film UD composites. Besides, the latter had higher adhesion strengths under the same processing conditions due to increased adhesion between the fiber and the resin. Next, high-density polyethylene (HDPE) modified SEBS resin was used as the matrix of the composites. Their interfacial adhesion strengths were found to increase slightly and the DMTA curves indicate that the crystallinity of the modified matrix increased with the content of HDPE resin. All of these benefit the improvement of the protection property of the composites. [Copyright &y& Elsevier]

Zirconia/polystyrene core-shell microspheres were prepared through room-temperature aging process and a solvothermal process with ethanol as solvent. Through the hydrolysis of zirconium propoxide, ZrO2 was coated on PS cores to form the core-shell microspheres. And hollow ZrO2 shells were formed by calcining the core-shell particles in a muffle oven under static air at 600 °C. [Copyright &y& Elsevier]