Effect of different solvents and concentration of polymer in the casting solution on the formation of PVDF membranes

Understanding the mechanism of asymmetric membrane formation is very important in order to produce membranes of desirable morphology.Porous asymmetric poly (vinylidene fluoride) (PVDF) membranes were cast with commercial-grade Kynar K760 polymer pellets and three different solvent systems: N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF) and 1-methyl-2-pyrrolidone (NMP), and with a focus on the PVDF/DMAc system, the effects of concentration of polymer on membrane formation were investigated. Flat-sheet membranes were prepared from a casting solution of polymer in various solvents by immersing the prepared films in nonsolvent-containing of water. The membranes were characterized using scanning electron microscopy (SEM). The differences of solubility parameters between the non solvent, solvent and PVDF affected the phase separation and the resultant morphology. An attempt was made to correlate the effect of the solvent on membrane morphology employing solubility parameters between solvent, non solvent and polymer

کلیدواژه ها:

Membrane ، Phase inversion ، Poly (vinylidene fluoride) ، Solvent ، Concentration of polymer