‘Green’ fabrication of PVC UF membranes with robust hydrophilicity and improved pore uniformity

Abstract

Hydrophilicity and pore uniformity are the key parameters for ultrafiltration (UF) membranes to avoid fouling and ensure separation effectiveness. In this paper, a simple ‘green’ in-situ chemical reaction assisted phase separation method was studied, in which amine molecules bearing hydrophilic hydroxyl groups were grafted onto polyvinyl chloride (PVC) chains in dissolution process without initiator. The influence of modifier concentration on the structure, separation and anti-fouling performance of the PVC membranes was studied. The results indicated that the robust hydrophilicity, and high pore size uniformity and porosity of were achieved by properly anchoring preferable amine molecules. The pure water flux of the modified membrane was 261.5 L·m−2·h−1, BSA rejection was 99.1 % when 10 wt% SRN was added. Approximately 27 % increase of rejection to BSA, and 10-fold pure water flux that of the pristine PVC membrane. Due to the stable existence of modifiers in the membrane, the improved membrane hydrophilicity was maintained through 320 h filtration and acid/alkali soaking tests. This study provides a simple modification approach to enhance PVC UF membrane hydrophilicity and pore uniformity.