The aim of this study was to apply experimental design in determining the order of magnitude as well as the intersectional interactions between various parameters affecting the microstructure of fabricated polyethylene membranes via thermally induced phase separation method. In this study, among various parameters, the polymer concentration, cooling bath temperature and film thickness were selected as the most effective variables on the structure of membranes. The analysis variance results showed polymer concentration and cooling bath temperature were identically significant. Film thickness effect, however, showed less importance than other parameters. Surface response plots showed that lower polymer concentration and film thickness and higher cooling bath temperature would result in higher porosity. The results of analysis of variance showed that the interactions among individual parameters are significant. However, with an increase in the cooling bath temperature and polymer concentration, the effect of film thickness on the porosity would be negligible.
