RESUMEN
An efficient and effective process for the production of high-performance anion exchange membranes (AEMs) is necessary for the commercial application of fuel cells. Therefore, in this study, quaternized poly vinylbenzyl chloride (QVBC) and polysulfone were composited with glycidyltrimethylammonium-chloride-quaternized chitosan (QCS) at different ratios (viz., 1 wt %, 5 wt %, and 10 wt %). The structure and morphology of the membranes were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. Further, the water uptake, swelling ratio, and ionic conductivities of the composite membrane at different wt % of QCS were evaluated. The membrane with 5% QCS exhibited an ionic conductivity of 49.6 mS/cm and 130 mS/cm at 25 °C and 70 °C, respectively.
RESUMEN
UV light and photocatalysts such as titanium dioxide (TiO(2)) and silver (Ag) are useful for disinfection of water and surfaces. However, the effect of UV wavelength on photocatalytic disinfection of spores is not well understood. Inactivation of Bacillus spores has been examined using different UV wavelengths and TiO(2) or TiO(2)/Ag composite materials. The level of UVA disinfection of Bacillus anthracis and Bacillus brevis vegetative cells increased with the presence of the TiO(2) and Ag photocatalysts, but had little effect on their spores. B. brevis spores were slightly more sensitive to UVB and UVC than the spores of B. atrophaeus. Photocatalytic sterilization against spores was strongest in UVC and UVB and weakest in UVA. The rate of inactivation of Bacillus spores was significantly increased by the presence of TiO(2), but was not markedly different from that induced by the presence of Ag. Therefore, TiO(2)/Ag plus UVA can be used for the sterilization of vegetative cells, while TiO(2) and UVC are effective against spores.