Experimental Design Applied to Fabrication of PSf Membranes via NIPS Method

This work involves non solvent induced phase separation method for fabrication of polysulfone (PSf) flat sheet membranes. N-Methyl-2-Pyrrolidon (NMP) serves as the solvent while poly (ethylene glycol) (PEG 20000) is used as additive. A full-factorial experimental design was employed for individual and mutual assessment of parameters in the membranes. In this case, the individual and mutual impacts of such parameters as the polymer concentration, PEG concentration and the coagulation bath composition were investigated on the final structure and function as well as the performance of membranes. The structural analysis included measurement of porosity and observation of SEM images. In order to assess the performance of membranes, mechanical strength measurement was applied. Comparing F-values in the table of data of analysis of variance (ANOVA) indicates that the significance of parameters differs in porosity analysis from tensile strength. The effective parameters in the porosity analysis include, in terms of priority, coagulation bath composition, polymer concentration and PEG concentration while in tensile strength analysis, PEG concentration overtakes polymer concentration. This issue could contribute to simultaneous optimization of porosity and mechanical strength.