A novel cockscomb-like substrate-supported TFN-FO membrane with a dispersed bovine serum albumin (BSA)/gold nanoparticles (GNPs) interface layer exhibiting high performance

A novel thin-film nanocomposite (TFN) forward osmosis (FO) membrane was fabricated by loading bovine serum albumin (BSA)/gold nanoparticles (GNPs) on the surface of a cockscomb-like nylon supporting membrane. The influence of the embedded BSA/GNPs on surface morphology, surface roughness, surface charge, separation, and FO performance of the TFN-FO membrane was investigated. The water flux of the BSA/GNPs-modified FO membrane could be increased to 55.2 ± 5.4 LMH, and the Js/Jw value was substantially decreased to 0.034 g/L, indicating a high selectivity of the modified membrane. BSA/GNPs located between the top of the nylon supporting membrane and the bottom of the polyamide (PA) skin layer provided passage for water transport and increased the roughness of the PA layer, thus enhancing the effective area on which the osmotic pressure could act. In addition, BSA/GNPs located at the bottom surface of the nylon supporting membrane provided a nearly electroneutral surface in the solution and alleviated dilutive concentration polarization. In summary, choosing a nylon membrane with a special cockscomb-like surface structure as the supporting layer to load BSA/GNPs nanoparticles proved to be a creative and effective nano-modification method for fabricating high-performance TFN-FO membranes.