SummaryTransport of liquids by pervaporation takes place by a solution-diffusion mechanism. In order to investigate the "solution part" of this transport model, preferential sorption has been compared with preferential permeability. Sorption equilibria and pervaporation experiments for the systems water-ethanol-cellulose acetate, water-ethanol-polyacrylonitrile and water-ethanol-polysulfone have been investigated. Theoretical values of preferential sorption have been derived from Flory-Huggins thermodynamics, extended with concentration dependent interaction parameters. These calculated sorption values show a reasonable agreement with experimental values. The large difference in molar volumes between water and ethanol determines the preferential sorption of water in these systems to a great extent, and this effect increases with decreasing swelling value. Comparison of preferential sorption experiments with pervaporation experiments indicates that, apart from the effect of differences m diffusivity for the permeating components, preferential sorption contributes to a major extent to selective transport

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The 'Electro-Membrane Processes and Bipolar Membrane Technology' conference took place on 25-27 October 2000 at the University of Twente, The Netherlands. Here, we outline some of the presentations which were given at the event.The conference, which marked the closing event of the activities of the EU Thematic Network on Bipolar Membrane Technology, was attended by 65 participants from 13 different countries.Compared with the workshops, the number of people coming from outside the network increased.Whereas the number of people from inside the network remained roughly the same -28 compared with 26 in Montpellier -the number of people from outside the network was larger -37 attendants compared with 14 in Montpellier.