Tailoring microstructure and physical properties of poly(vinylidene fluoride-hexafluoropropylene) porous films

This paper presents a systematic study for the production of poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)], porous films using solvent evaporation (SE) and non-solvent-induced phase separation (NIPS) techniques. Parameters such as volume fraction of the copolymer solution, film thickness, time exposure to air, non-solvent, and temperature of the coagulation bath were investigated on the morphology, crystallization, and mechanical properties of the samples. Films with different porous morphologies including homogeneous pore sizes, macrovoids, and spherulites were obtained depending on the processing conditions, which in turn affect the wettability and mechanical properties of the material. Knowing that the phase content of the films also depends on the processing conditions, this paper shows that P(VDF-HFP) films with tailored porous morphology, electroactive phase content, hydrophobicity, crystallinity, and mechanical properties can be achieved for a specific application using the adequate SE and NIPS techniques conditions.