Preparation of antimicrobial PVDF and EVOH membranes by grafting quaternary ammonium compounds

Dimethyl octadecyl [3-(trimethoxy silyl) propyl] ammonium chloride (DMOAP) was grafted on polyvinylidene fluoride (PVDF) membranes and ethylene-vinyl alcohol copolymer (EVOH) membranes, and the effects of preparation conditions on the grafting rate and antimicrobial performance of the membranes were investigated. The result showed that the grafting rate of membranes increased with the increased DMOAP concentration. The ion exchange capacity rose first and then declined with the increase of reaction temperature and time. The membranes displayed excellent antimicrobial performance against Escherichia Coli . The EVOH membranes also showed good stability, remaining 86% of the initial ion exchange capacity after the cyclic soaking test (312 h). The modified membranes showed excellent antimicrobial performance. • Quaternary ammonium compounds were grafted on PVDF membranes and EVOH membranes. • The effects of preparation conditions on the grafting rate were discussed. • The antimicrobial performance of the membranes was tested. • The stability of the membranes was investigated.