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Abstract: Silver (Ag) nanowires were fabricated from silver chloride (AgCl) by the hydrothermal method. The successful formation of Ag nanowires relied on the low solubility of AgCl as a precursor and the structural change of glucose to polymer on the Ag nanowire (protective layer). The Ag+ ion concentration in the reaction solution containing AgCl was initially low, but after a reaction time of over 12h, Ag+ gradually reduced to Ag metal. Transmission electron microscope, Raman spectrometery, and X-ray photoelectron spectroscopy revealed that the surface of the obtained Ag nanowires possessed a carbon-rich layer with a carboxyl group, and the Ag+ ion coordinated with the carboxyl group of this layer. The difference in the surface-free energy of Ag crystals changed the crystal growth rate that impelled the anisotropic growth of the Ag particles. By examining various reaction conditions, it was determined that the ratio of Cl− to Ag+, reaction temperature, and reaction time are important factors for successful preparation of Ag nanowires. Under the reaction condition that the molar ratio of Cl− to Ag+ at 160°C for 24h is above equimolar concentration, uniform Ag nanowires were successfully prepared. [Copyright &y& Elsevier]

The influence of heating conditions on the structure of hollow carbon fibers (H-CFs) during their fabrication from solid poly(vinyl alcohol) (PVA) fibers is reported. The hollow structure of PVA-derived carbon was formed by selective iodination and subsequent stabilization of precursor PVA fiber close to the fiber surface followed by carbonization. The broadening of X-ray diffraction peaks due to disorder and the small size effects of the (002) plane were strongly reduced by increasing the heat treatment temperature (HTT) from 800 to 3000 °C, but the asymmetric shape of (10) and (110) reflections suggests turbostratic layer stacking. The increase of HTT to 3000 °C increased the degree of graphitization evident from the decrease of interplanar spacing from 0.360 to 0.338 nm and the intensity ratio of D to G bands in Raman spectra from 0.93 to 0.58. The crystallite size, orientation and electrical conductivity of the resultant H-CFs were also improved with higher HTT. Besides, the size of the hollow core was also influenced by the HTT and both wall thickness and carbon yield decreased with higher HTT. The core of the H-CFs could be easily filled with polymer by bulk polymerization of monomer. [ABSTRACT FROM AUTHOR]

PVA is reinforced with SWCNTs using green tea extract as a dispersant to achieve good dispersion of the SWCNTs in an organic solvent and finally high-performance composite fibers. A combination of green tea extract/DMSO/SWCNT/PVA is found to disperse larger aggregates of SWCNTs to individual or thin bundles of a few nanotubes. Incorporation of 0.5 wt% SWCNTs into PVA fibers yields a tensile strength of 2.42 GPa, a Young's modulus of 46 GPa, toughness of 105 J · g−1 at a failure strain of 11%, and a loop strength of 245 MPa, much higher than the values of commercial PVA fibers. The incorporation of highly dispersed SWCNTs suppresses the fibrillation tendency of the PVA fibers. The applied load is effectively transferred from the matrix to the SWCNTs. [ABSTRACT FROM AUTHOR]

• Cellulosic non-woven fabrics were prepared from ionic liquid solutions. • Suitable molecular weights of cellulose contributed to forming ultrafine fibers. • Fiber diameter was reduced and strength was improved as air velocity increased. • Ultrafine cellulose fibers with a high strength of ca. 940 MPa were obtained. A wet-type solution blow spinning system equipped with a single concentric nozzle was assembled to investigate the key factors for preparing ultrafine regenerated cellulose fibers. The effects of the degree of polymerization (DP) of cellulose and the velocity of blown air on fiber morphology were studied by rheological analyses and scanning electron microscopy. The results demonstrated that cellulose with a DP of 2365, together with a high air velocity, could aid the formation of continuous ultrafine fibers. Fluid filament deformation was observed using a high-speed camera and clearly correlated with the final fiber morphology. Additionally, aligned ultrafine fibers were spun on a rotational collector and their mechanical properties and structural parameters were characterized. Ultrafine cellulose fibers with a high strength of 941.4 MPa and a high crystallite orientation of 0.909 were obtained. [ABSTRACT FROM AUTHOR]

Abstract: Many textiles have been often used in marine environments for a wide variety of purposes. Consequently, effective and clean methods to prevent biofouling in these textiles are needed. In this study, a nylon mesh doped with AgI was examined for its antifouling performance. The nylon mesh was iodinated with an iodine–potassium iodide aqueous solution and subsequently immersed in silver nitrate solution to form AgI particles in the fiber. SEM-EDX analysis indicated that the AgI crystals were highly incorporated into the nylon 6,6 polymer (173wt% gain). The bactericidal activity of AgI-doped nylon mesh was more than 200 times higher than that of silver-coated nylon mesh. Furthermore, continuous prevention of biofouling in the coastal marine environment was attained for 437days by using the AgI-doped nylon mesh. Since the concentration of the released silver ions from the nylon mesh was estimated to be less than 1ppb, the proposed nylon mesh is useful as an effective and clean method for prevention of biofouling in polymer textiles. [Copyright &y& Elsevier]