Acrylonitrile-Based Copolymer Membranes Containing Reactive Groups: Surface Modification by the Immobilization of Poly(ethylene glycol) for Improving Antifouling Property and Biocompatibility

Abstract

The antifouling property and biocompatibility of a polyacrylonitrile-based copolymer membrane were improved by the immobilization of poly(ethylene glycol) (PEG) on the membrane surface. The studied membranes were fabricated from poly(acrylonitrile-co-maleic acid), in which the carboxyl groups could be conveniently conversed into anhydride and then esterified with poly(ethylene glycol). Chemical and morphological changes on the membrane surface were characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), scanning electron microscopy (SEM), and sessile drop contact angle measurements (CA). It was found that the water contact angle of the membrane was reduced and the biocompatibility corresponding to platelets adhesion and protein adsorption was improved significantly with the immobilization of PEG chains on the membrane surface. Furthermore, the permeation behaviors of the base and modified membranes were investigated by bovine serum albumin (BSA) filtration experiments. Membranes containing hydrophilic carboxyl groups or PEG chains showed higher solution flux, lower BSA adsorption, and better flux recovery after cleaning than those of polyacrylonitrile membranes. Particularly, compared with polyacrylonitrile membranes, the PEG-immobilized membrane showed a 6-fold increase in BSA solution flux, 63% reduction in total fouling, and 67% reduction in BSA adsorption.