Preparation and characterization of polyamide-urethane thin-film composite membranes

We attempted to produce reverse osmosis membranes with 5-chloroformloxy-isophthaloyl chloride (CFIC) and m-phenylenediamine (MPD) with an interfacial polymerization technique on the polysulphone supporting film. The membranes produced were characterized using permeation experiments with salt water. Attenuated total reflectance infrared (ATR-IR), X-ray photoelectronic spectroscopy (XPS), as well as imaging using scanning electronic microscopy (SEM) were used. The results show that the active layer of a CFIC/MPD TFC membrane is polyamideurethane, including an amide functional group (-CONH-), urethane functional group (-OCONH-) and hydroxyl functional group (-OH). The flux and rejection of a CFIC/MPD TFC membrane are better than a TMC/MPD TFC membrane in the same condition (concentrations of CFIC = 0.15 wt% and contact time with the organic solution is 20 s, which is the best preparation parameter) and the surface of the CFIC/MPD TFC membrane is a dense, finely dispersed grainy structure.