Unusual trend of increasing selectivity and decreasing flux with decreasing thickness in pervaporation separation of ethanol/water mixtures using sodium alginate blend membranes

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• 作者：Eoin J. Flynn ; Donal Keane ; Justin D. Holmes ; Michael A. Morris ; ^{m.morris@ucc.ie}
• 关键词：Selectivity ; Flux ; Sodium-alginate ; Pervaporation ; Glass transition temperature
• 刊名：Journal of Colloid and Interface Science
• 出版年：2012
• 出版时间：15 March 2012
• 年：2012
• 卷：370
• 期：1
• 页码：176-182
• 全文大小：1051 K

文摘

Pervaporation membranes were produced comprising a 4:1 sodium-alginate:poly(vinyl-alcohol) polymer blend selective layer with a plasticizing agent (glycerol). Membranes were supported on a poly(acrylonitrile) mesoporous support layer and non-woven fabric base. Pervaporation separation of ethanol/water mixtures was carefully followed as a function of film thickness and time. It was found, contrary to what might be expected from literature, that these films showed increased selectivity and decreased flux as film thickness was reduced. It is argued that the morphology and structure of the polymer blend changes with thickness and that these structural changes define the efficiency of the separation in these conditions.