Study On Preparation And Performance Of Functional Polyethersulfone Membranes

Charged surface modification is an effective strategy to improve and enhance the membrane performance. In this paper, positively charged polyethersulfone ultrafiltration membranes were prepared through quaternization of chloromethylated polyethersulfone/polyethersulfone (CMPES/PES) blend membranes.In the first part of this paper, chloromethylated polyethersulfone was synthesized by using chloromethyl ether as a reactant. The effects of reaction temperature, time and dosage of chloromethyl ether on the chloromethylation degree were investigated. Zwitterionic polyethersulfone was prepared from CMPES by grafting imidazole and1,3-propanesultone, successively. The chemical structure and thermal stability of resulted polymers were characterized by FTTR,1H NMR and TGA, respectively.In the second part, CMPES/PES blend ultrafiltration membranes were fabricated by non-solvent induced phase separation (NIPS) technique, and then quaternized with tertiary amines to get series of positively charged polyethersulfone ultrafiltration membranes. Effects of various amines on the performance of the blend membranes were studied, meanwhile, the relationship between chemical structure and performance of positively charged polyethersulfone membranes were carefully discussed. It was found that, quaternization of CMPES/PES blend membrane significantly improved both the hydrophilicity and water flux, therefore, contributed a lot to the separation for basic dyes, but little to acid dyes. For triethanolamine or N,N-dimethyl glycine modified membrane, the Alcian Blue8GX (AB) rejection are attained99%.