MEMBRANES FORMATION BY SUPERCRITICAL FLUIDS

摘要

The generation of microporous cellulose acetate and polymethylmethacrylate (PMMA) membranes has been studied using a supercritical fluid based phase inversion process in which CO_2 acts as the non-solvent. Some experiments have been performed at 200 bar and 45°C with 20% w/w concentration of PMMA in dimethylsulfoxide (DMSO) and with concentrations ranging from 20 to 40% w/w of cellulose acetate in acetone. The structure of the resulting membranes has been analysed using scanning electron microscopy. We obtained membranes with a mean pore diameters ranging from 2 to 20μm and a dense skin surface. Further experiments will be performed to investigate the effect of the other process parameters on these membranes morphology and pore sizes.