Amphiphilic surface construction and properties of PVC-g-PPEGMA/PTFEMA graft copolymer membrane

Abstract

Inspired of the synergistic effect of the antifouling performance of hydrophilic substance and the self-cleaning function of low surface energy material, we designed and synthesized a kind of macromolecule amphiphilic graft copolymer by the free radical polymerization, which used polyvinyl chloride (PVC) as the main chains, poly(ethylene glycol) methacrylate (PEGMA) as the hydrophilic segment and trifluoroethyl methacrylate (TFEMA) as the low surface energy segment. Then, the amphiphilic PVC-g-PPEGMA/PTFEMA graft copolymer membrane was successfully prepared via surface segregation through the phase inversion process and was further optimized via the forced self-assembly through annealing treatments. The results showed that the PPEGMA chain segments migrated on the membrane surface which driven the PTFEMA chain segments to enrich on the membrane surface during the annealing process, meanwhile, annealing treatment promoted the local microphase separation and improved the mean pore size and the porosity. Based on the synergistic effect of hydrophilic and low surface energy segments, the PVC-g-PPEGMA/PTFEMA graft copolymer membrane obtained the maximum pure water flux of 510.69 ± 16.28 L∙m⁻²∙h⁻¹, flux recovery rate of 91.49% and rejection rate of 99.31% in the BSA filtration process, which also revealed significantly antifouling properties. More importantly, the PVC-g-PPEGMA/PTFEMA copolymer membrane exhibited long-time hydrophilic stability, which could extend its potential service life.