High performance ultrafiltration membrane composed of PVDF blended with its derivative copolymer PVDF-g-PEGMA

Amphiphilic graft copolymers were fabricated from a poly(vinylidene fluoride) (PVDF) backbone that was grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) (PVDF-g-PEGMA) using atom transfer radical polymerization (ATRP) method. An intriguing membrane of periodic pillar-like or sphere structures was formed using PVDF/PVDF-g-PEGMA block copolymer mixtures that were dissolved in suitable solvents. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, and flux performance tests were conducted to determine the membrane characteristics. The results show that the defect-free high performance ultrafiltration membrane can be fabricated by adding 10 wt% or 15 wt% PVDF-g-PEGMA to the PVDF backbone material using the phase inversion method. The permeate fluxes of the fabricated membrane with 10 wt% and 15 wt% PVDF534 K-g-PEGMA are 5110 (L/m2 h bar) and 5170 (L/m2 h bar), respectively, for deionized water under 0.07 MPa. The TOC (sodium alginate) removal efficiencies of PVDF membranes with 10 wt%, and 15 wt% PVDF534 K-g-PEGMA are 90.97%, and 87.19%, respectively. Furthermore, the removals of Suwannee River humic acid that contained 2 mM CaCl2 and 10 mM Ca(OH)2 for the PVDF membrane with 10 wt% PVDF534 K-g-PEGMA are 72.11% and 77.69%, respectively. This defect-free high-performance membranes show good potential for water treatment applications.