Polymeric membranes are widely used in separation, purification and fractionation process. The major disadvantage for their application in industries is their hydrophobicity. Modifications including coating and grafting of hydrophilic materials onto the membrane surfaces have been investigated to improve hydrophilicity.

The team led by Prof. WAN Yinhua from Institute of Process Engineering, Chinese Academy of Sciences made antifouling ultrafiltration membranes with excellent hydrophilic surface from PAN-b-PEG copolymers. The introduction of hydrophilic PEG chain greatly improved membrane hydrophilicity. X-ray photo-electronic (XPS) and contact angle measurements confirmed the enrichment of PEG segments in membranes.

Scanning electron microscope (SEM) and protein static absorption experiment results showed that PAN-b-PEG copolymer membranes had a typical asymmetric structure similar with PAN membranes but exhibited better antifouling ability for bovine serum albumin (BSA). The effects of copolymer composition and PEG chain length on the structure and property of PAN-b-PEG membranes were studied. As PEG content increased in the copolymer, the hydrophilicity and antifouling ability of copolymer membranes increased. There was no obvious effect of PEG chain length on these properties of PAN-b-PEG membranes.

This work was financially supported by the National Nature Science Foundation of China (21104086) and the National Key Laboratory of Biochemical Engineering, IPE. The research work has been published on Journal of Membrane Science.