Investigation of liquid-liquid demixing and aggregate formation in a membrane-forming system by means of pulse-induced critical scattering (PICS)

Phase separation phenomena in the quasi-ternary system cellulose acetate (CA)/dioxane/water, used as a typical system in the preparation of polymeric membranes for ultrafiltration and reverse osmosis applications, were investigated by means of pulse-induced critical scattering (PICS). Both the cloud point curve and spinodal curve were determined for CA concentrations up to 20% (w/w). The influence of maleic acid (used as an additive in order to improve the membrane performance) on the position of the binodal and spinodal curves and the demixing kinetics were investigated.