Effect of Non-Solvents Used in the Coagulation Bath on Morphology of PVDF Membranes

The aim of this paper was to prepare a poly (vinylidene fluoride) (PVDF) membrane using different non-solvents in the coagulation bath for the phase inversion method. In order to increase the mechanical strength of membranes, facing the pressure of work, was used a macro-porous polyester support. The morphology and structure of the resulting membranes were evaluated by scanning electron microscopy, porosity measurements, water and 1-octanol uptake, contact angle, pure water flux, hydraulic permeability and hydraulic resistance. The morphology and pure water flux changed significantly using ethanol (symmetric membrane) and/or water (asymmetric membrane) as the non-solvent. The symmetric membrane presented a high hydrophobic surface (water contact angle similar to 136 degrees) and a higher pure water flux and porosity than the asymmetric membrane, which presented a lower hydrophobicity surface (water contact angle similar to 90 degrees). The morphologies obtained suggest different applications.