Effect of TiO ₂ nanoparticle size on the performance of PVDF membrane

The comparison of the performance and morphology was carried out between neat PVDF membrane and PVDF composite membranes with nanosized TiO ₂ particles of different size. The results of permeability and instrumental analysis illustrated that nanometer size obviously affected the performance and structure of the PVDF membranes. The smaller nanoparticles could improve the antifouling property of the PVDF membrane more remarkably. The surface and cross-section of the membranes were observed with an atomic force microscopy (AFM), a scanning electron microscope (SEM). The TiO ₂ /PVDF membrane with smaller nanoparticles had smaller mean pore size on its surface and more apertures inside the membrane. X-ray diffraction (XRD) experiments also suggested that smaller TiO ₂ nanoparticles had stronger effect on the crystallization of PVDF molecules.