Surface modification of polyvinylidene fluoride pervaporation membranes

Polyvinylidene fluoride (PVDF) membranes were surface-modified using fluorinated surface-modifying macromolecules (SMMs) additives. The membranes were prepared using the phase-inversion method. Two novel SMM formulations were used. The effect of some relevant parameters, such as the solvent evaporation time, evaporation temperature, and concentration of SMM in the PVDF casting solution, was considered The prepared membranes were characterized in terms of the contact angle analysis, the liquid entry pressure of water measurements, and the scanning electron microscopy. Pervaporation experiments were conducted for dilute chloroform/water binary mixtures. Based on the contact angle analysis, the incorporation of SMM into the PVDF casting solution produced membranes with higher surface hydrophobicity. The pervaporative performance of the prepared membranes was investigated, and the relationship between the surface characteristics of the modified PVDF membranes and the chloroform separation discussed.