Anti-Fouling Performance of Mixed Matrix PVDF Membranes with Mono-Hydroxyl Poly(dimethylsiloxane) (PDMS-OH) Grafted Silica Nanoparticles

In this study, we investigate the use of surface-modified silica nanoparticles to improve the anti-fouling performance of PVDF ultrafiltration membranes. Here, 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 at a range of nanoparticle concentrations (0, 1.6, 3.2, 6.3, and 11.8%) to understand how PDMS modified silica content affected 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, in order to determine how morphological features of the nanocomposite membranes affected fouling and pure water flux. 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 change in the porosity, mean pore size and the hydrophilicity of the membrane caused the rejection rate to be increased significantly. 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.