ABSTRACT
The pervaporation performances of polydimethylsiloxane-polystyrene interpenetrating polymer network (PDMS-PS IPN) layers supported on polyethersulfone (PESF) ultrafiltration membranes for ethanol–water mixtures were investigated. The PDMS-PS IPN layers were prepared via the sequential IPN technique. The mechanical properties and the film-forming capability of the PDMS-PS IPN are superior to those of the crosslinked PDMS. An inversion of the selectivity of PDMS-PS IPN layers supported on PESF membranes was observed; at low ethanol concentrations in the feed, the membrane was more selective for ethanol, while at high concentrations it was more selective for water. An explanation is suggested for this inversion. For a mixture containing 10 wt% ethanol, which is of interest in biotechnology, the membrane was ethanol selective, and the permeation rate and separation factor of the PDMS-PS IPN supported membrane at 60°C, with a crosslinked PS content of 40 wt%, were 160 g/m2 h and 5.5, respectively.
