The effect of PEG concentration and coagulation bath composition on the morphology of microporous PSf membrane prepared via NIPS method

Flat sheet polysulfone (PSf) membranes were prepared via non-solvent induced phase separation (NIPS) process using N-methyl-2- pyrrolidone (NMP) as a solvent. Polyethyleneglycol (PEG-20000) in different concentrations was used as a polymeric additive in the casting solution. Since the effect of coagulant bath composition in presence of PEG as polymeric additive on the morphology of membranes has not been deeply considered, the mixture of DI water and NMP was used as aqueous coagulant bath. In this work the effect of PEG concentration in casting solution and the composition of coagulation bath on the membrane morphology were examined. The microporous structure and performance of membranes were investigated by SEM technique and water permeation test, respectively. Obtained results showed that, increasing the amount of PEG decreases the mechanical strength. The morphology of membranes prepared at two different bath compositions showed that by changing the bath composition from pure water to 60 wt% NMP, the number of finger-like macrovoids in the structure of membrane decreases.

کلیدواژه ها:

Phase inversion ، Coagulation bath ، Macrovoid ، PSf ، PEG