Surface Modification of Electrospun Poly(vinylidene fluoride) Fibrous Membrane Based on Layer-by-Layer Assembly of TiO2 Nanoparticles

摘要

A facile surface modification method of improving hydrophilicity of poly(vinylidene fluoride) (PVDF) membranes was presented by layer-by-layer assembly. Various layers of anatase TiO2 nanoparticles were successfully deposited on electrospun PVDF fibrous membranes. FTIR, SEM, TEM and droplet scanning analysis were used to investigate microstructure and contact angle (CA) of modified membranes. TiO2 modified PVDF fibers showed rougher surface and greater diameter compared to uncoated ones. The CA of modified membranes was significantly decreased. For instance, the CA of the 4 layers of TiO2 modified membranes through two pretreatmentmethods (viz., ethanolwater displacement or KMnO4 modification) could be decreased to 0 degrees while the unmodified PVDF had CA of 114.4 degrees. Moreover, the modification through ethanol-water pre-treatment formed TiO2 coating owing to hydrogen bonds without damaging strength of PVDF. Therefore, this presents a facile and effective hydrophilic modification method for PVDF in water treatment, filtration and other fields.