Antifouling enhancement of poly(vinylidene fluoride) microfiltration membrane by adding Mg(OH)2 nanoparticles

Mg(OH)2 nanoparticles were mixed into poly(vinylidene fluoride) (PVDF) with PEG as an additive to prepare hybrid membrane by phase inversion. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) measurements were performed, and the ultrasonic stability, porosity, hydrophilicity, permeation and bovine serum albumin (BSA) and Escherichia coli (E. coli) adsorption of the membrane were investigated. As revealed by FTIR spectra, large amount of –OH groups were exist in the hybrid membrane due to the addition of Mg(OH)2 nanoparticles, and these –OH groups are responsible for the hydrophilicity increase of the modified membrane. BSA and E. coli adsorption measurements confirm that hybrid membrane exhibited higher antifouling property than the original PVDF membrane, as the number of adsorbed proteins and bacterial cells on the membrane surface were reduced dramatically. PEG and Mg(OH)2 had mutual effects on the resulting structures and properties including porosity and permeability of the membrane. The superiority of the PVDF/Mg(OH)2 membrane in filtering bacterial solution was significant, as the resistances with respect to time decreased dramatically with 10 wt.% Mg(OH)2 added, suggesting it would be very effective in preventing flux losses caused by biofilm formation.