Formation Mechanism and Properties of Polyvinylidene Fluoride (PVDF)/Nano-Silica Hybrid Membranes
By means of the wet phase inversion process, the PVDF/silica (SiO2) hybrid membranes with different content of nano-silica (nano-SiO2) were prepared. It was investigated that the pure water flux and retention based on egg albumin solution for different PVDF hybrid membrane samples. The pure water flux and porosity of PVDF/SiO2 hybrid membranes are enhanced simultaneously with increasing SiO2 content in PVDF composite system. When SiO2 content is around 7.5%, the phase separation rate of casting solution increases to peak value, meanwhile, the retention of hybrid membrane achieves the best effect. The SEM micrographs show that the quantity of finger-like pores of PVDF/SiO2 hybrid membranes decreases and the micropores becomes fine compared to PVDF membrane. The results of DSC indicate that there are almost no effects on the melting point, but enhancement the fusion enthalpy and the crystallinity of PVDF along with increasing the SiO2 content.