Antifouling performance of mixed matrix PVDF membranes with mono-hydroxyl poly(dimethylsiloxane) (PDMS-OH) grafted silica nanoparticles

Abstract

In this study, surface-modified silica nanoparticles were used to improve the antifouling performance of PVDF ultrafiltration membranes. Fouling resistant nanoparticles were prepared by grafting monohydroxy-polydimethylsiloxane onto the surface of silica nanoparticles using Steglich esterification. The mixed matrix PVDF membranes were prepared with different nanoparticle concentrations to understand the effect of PDMS modified silica on membrane performance. The resulting hybrid membranes were characterised using a range of techniques including scanning electron microscopy (SEM), water contact angle (CA), porosity, and pore size measurements. Embedding silica nanoparticles resulted in a significant reduction in membrane fouling, including lower protein adsorption and a flux recovery ratio of 97 %. Although water flux was reduced by the addition of nanoparticles, the foulant rejection rate was increased significantly due to the changes in porosity and hydrophilicity of the membranes. Together, these results are of particular benefit to the ultrafiltration industry, where improved antifouling and flux recovery can help reduce operating and maintenance costs in these membrane processes.