Modification and characterization of TFC membranes with Ag nanoparticles: application in seawater desalination

New composite membranes were developed and characterized for application in reverse osmosis. A commercial TFC membrane surface was modified, impregnating with Ag nanoparticles (AgNP) (5 mg, 10 mg and 15 mg per 100 mL DI water) via interfacial polymerization to improve biofouling resistance. The effects on permeate flow, operating pressure and salt rejection were assessed, with rejections of 97.6%, 97.8% and 96.7% using 5 mg, 10 mg and 15 mg, respectively. The contact angle for the 10 mg AgNP membrane (39.01 ± 4.43) showed higher hydrophilicity (> 19%) than the commercial BW30XFR membrane. Infrared spectroscopy results showed membrane modifications by signals at 1717 cm−1 and 1616 cm−1 indicating a new layer of polyamide. AFM, SEM and EDS results determined an agglomerate size for the 10 mg AgNP membrane of 3.93 µm ± 0.93 and 169.9 nm RMS roughness. The anti-biofouling properties of modified membranes were tested against Bacillus halotolerans MCC1. The results showed a highly significant reduction of biofilm cake layer, total cells, and total organic carbon on the surface of the modified membranes (72%, 48% and 45% lower) using 5 mg, 10 mg and 15 mg, respectively.