ABSTRACT
A novel positively charged N-[(2-hydroxy-3-trimethylammonium)propyl] chloride chitosan (HTCC)-Ag/polyethersulfone (PES) composite nanofiltration membrane was easily prepared by coating the active layer, HTCC, onto PES as the support through epichlorohydrin as the cross-linking reagent and nano-Ag particles as the introduced inorganic components. Scanning election microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray diffraction were employed to characterize the morphology of the resultant membranes, of which the molecular weight cut-off was about 941 Da. At 25 °C, the pure water permeability is 16.27 L/h·m(2)·MPa. Our results showed that the rejection of pharmaceuticals and personal care products (PPCPs) followed the sequence: atenolol > carbamazepine > ibuprofen, confirming that the membranes were positively charged. The antibacterial properties of the membranes were compared to elucidate the existence of Ag nanoparticles which help to improve antibacterial activity against Gram-negative Escherichia coli (DH5α, Rosetta) and Gram-positive Bacillus subtilis. The inhibition zone diameters of HTCC-Ag/PES membranes towards E. coli DH5α, E. coli Rosetta and Bacillus subtilis were 17.77, 16.18, and 15.44 mm, respectively. It was found that HTCC-Ag/PES membrane has a better antibacterial activity against E. coli than against Bacillus subtilis, especially for E. coli DH5α.
