Browsing by Author "Ferreira, Juanita"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    The separation of ethanol-hexane mixtures by pervaporation
    (Stellenbosch : Stellenbosch University, 1900) Ferreira, Juanita; Sanderson, R. D.; Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science.
    ENGLISH ABSTRACT: Pervaporation experiments, using polyvinyl alcohol (PVA) and modified PVA membranes cast on permeable polyether sulfone substrates, were performed with ethanol-hexane mixtures. The modified PVA membranes comprised a specially synthesized and well defined series of poly(acrylic acid-co-vinyl alcohol-cohydroxyethyl- acrylate) terpolymers. Experimental variables were investigated. Variation of membrane thickness showed that at least two polymer layers were necessary. The effect of changing the binary feed ratio was that selectivity increased with increasing ethanol content. Pretreatment proved to be effective in terms of both flux and selectivity. Increasing hydrophilicity in the chemical structure of the membrane caused a decrease in the selectivity for ethanol, i.e. GFT-standard (3 300); GFT-wasserreich (270); Gantrez AN 119 (15); best synthesized terpolymer (2 200). These values were measured with a 5% ethanol mixture.