Effect of mixed SiO2 nanoparticle/TiO2 sol on structure and performance of PVDF composite membranes

Mixed TiO2 sol and SiO2 nanoparticles in different proportions were added into PVDF membrane, and their effects on pure water flux, retention rate and mechanical properties of PVDF membrane were discussed. The SiO2-TiO2/PVDF membrane surface and section structures were characterized by SEM, FT-IR, and XRD analyses. In addition, membrane mechanical properties and hydrophilicity were tested. The results indicated that mixed TiO2 sol and SiO2 nanoparticles could increase both hydro-philic and mechanical strength of PVDF membrane. When the SiO2/TiO2 mixed ratio was 3:10, membrane performance was optimized (porosity 81%, flux 13.9 L.m(-2).h(-1).KPa, retention rate 78%, tensile strength maximum loading 50N, tensile stress 3.18MPa, tensile strain 18%).