XPS and contact angle characterization of surface modified cellulose acetate membranes by mixtures of PMHS/PDMS Original Research Article

A mixture of polymethylhydrosiloxane (PMHS) and polydimethylsiloxnae (PDMS) is used for modifying the surface of reverse osmosis and nanofiltration membranes. The porous substructure made of cellulose acetate (CA) was obtained by a phase separation process from acetone/formamide (2/1 wt/wt) casting solutions. Two polymer concentrations (22 and 25 wt.%) were used with a heat post-treatment temperature (80 °C) in order to produce membranes with pore sizes responding to nanofiltration and reverse osmosis needs. Overcoating the CA substructure with a PMHS–PDMS thin layer gave rise to the composite membranes.