Improving the permselectivity and antifouling performance of reverse osmosis membrane based on a semi-interpenetrating polymer network

Thin-film composite (TFC) reverse osmosis (RO) membranes whose ultrathin selective layer is composed of polyamide (PA) have been extensively employed in desalination and purification of water. However, the poor permeability , selectivity , and antifouling properties have limited their application, thus prompting several studies. In this study, a semi-interpenetrating polymer network (semi-IPN) based on PA and poly (N-vinyl-2-pyrrolidone) (PVP) was fabricated via in situ polymerization to enhance the permselectivity and antifouling property of RO membrane. The successfully fabricated PA/PVP semi-IPN was characterized using Fourier transform infrared (FT-IR), zeta potential , and X-ray photoelectron spectroscopy, X-ray diffraction measurements. Atomic force microscopy and water contact angle measurement showed that the hydrophilicity of the membrane was substantially improved. The optimal resultant membrane (0.5–10s-NVP) showed 43.2% and 0.2% increments in water flux and salt rejection, respectively. Furthermore, the antifouling performance was substantially improved; the 0.5–10s-NVP exhibited a lower decline ratio in the normalized water flux after the bovine serum albumin fouling process. Furthermore, the good stability of the semi-IPN was revealed via FT-IR after a 7-d continuous crossflow test. This work provides a guideline for physicochemical properties and microstructural design of novel RO membranes.