Preparation of hydrophobic PVDF/PVC/nano-graphite composite membrane and its self-cleaning properties

In this study, novel physical blending modified membranes are prepared using the non-solvent induced phase separation method, the influences of nano-graphite and Poly(vinyl chloride) (PVC) incorporated into the hydrophobic performance of the polyvinylidene fluoride (PVDF) membrane were investigated. The composite membrane was prepared not only reduces the cost of producing PVDF membrane, but also enhances the hydrophobicity of the membrane. The addition of nano graphite and PVC accelerated the phase transformation of PVDF and changed the crystal structure of PVDF. Therefore, the surface roughness of the composite membrane is changed, and the hydrophobicity of the composite membrane is enhanced compared with the original PVDF membrane. the crystal structure and crystallinity of the composite membranes can be analyzed by WAXD and DSC, the surfaces morphology of the composite membranes were characterized by SEM and AFM, the wetting and hydrophobicity of the composite membrane by CA and SFE. The experimental results show that adding a small amount of nano inorganic substance (nano graphite) to the (PVDF-PVC) blend polymer is an effective method to prepare and improve the hydrophobic performance of the blend polymer membrane. The PVDF-PVC/nano-graphite prepared in the experiment not only improves the hydrophobic performance of the PVDF membrane, but also reduces the cost of the composite membrane through the addition of PVC. Meanwhile, the membrane has a durable self-cleaning performance, which widens the applications of PVDF membranes.