INFLUENCE OF ZEOLITES IN PDMS MEMBRANES - PERVAPORATION OF WATER/ALCOHOL MIXTURES

A strong influence of the zeolite was found on the pervaporation of alcohol/water mixtures using filled PDMS membranes. In all cases, the zeolites reduced the swelling of the PDMS. Incorporation of the hydrophilic zeolite Y increased water fluxes, while ZSM-5 reduced both water and alcohol fluxes due to a partial retention of these molecules in the zeolite. For branched alcohols, the extreme importance of diffusion led to a strong dependency of selectivity and flux on temperature. Compared with commercially available PDMS membranes, better results were realized with the self-prepared membranes.