Modification and performance of PAN support membrane for composite nanofiltration membranes

PAN support membranes were prepared by wet phase-inversion method, and the membranes were modified in order to make the nitrile group hydrolyze into the carboxyl group. To compare the performances of the membranes before and after modifying, the membrane morphology was observed by means of environmental scanning electric microscopy (ESEM) and hydrophilicity was studied by the determination of contact angle of the membranes. Additionally, the membranes were investigated by the help of infrared spectrum (FTIR). The result showed that the modified membranes were more hydrophilic than the unmodified membranes due to the carboxyl groups on the former and the performances of the former were better than the latter.