Antifouling Membranes Prepared from Polyethersulfone Grafted with Poly(ethylene glycol) Methacrylate by Radiation-Induced Copolymerization in Homogeneous Solution.

To synthesize evenly grafted copolymers, gamma radiation of homogeneous solutions was employed to graft poly(ethylene glycol) methacrylate (PEGMA) onto polyethersulfone (PES). The grafting was verified by Fourier transform infrared spectroscopy, and the degrees of grafting (DGs) were determined by elementary analysis. The PES--polyPEGMA copolymers with different DGs were obtained by changing the monomer concentration. Membranes were cast from pristine PES, PES/PEG blends, and PES--polyPEGMA with different DGs, respectively, via nonsolvent-induced phase separation. Results from water contact angle measurements and scanning electron microscopy analysis indicated that increasing DGs led to PES--polyPEGMA membranes with increasing hydrophilicity and porousness. Filtration experimental results showed that increasing DGs without adding pore-forming agents caused PES--polyPEGMA membranes with higher permeability. Compared with PES/PEG membranes with analogous permeation characteristics, in which PEG is added as a pore-forming agent, PES--polyPEGMA membranes exhibited superior antifouling properties.