Dehydration of an ethanol/water azeotrope through alginate-DNA membranes cross-linked with metal ions by pervaporation

作者：Uragami Tadashi^*; Banno Masashi; Miyata Takashi

来源：Carbohydrate Polymers, 2015, 134: 38-45.

DOI：10.1016/j.carbpol.2015.07.054

• Pervaporation
• Sodium alginate
• DNA
• Ionic cross-linking
• Membrane
• Dehydration of azeotrope
• Soution-duffusion model

To obtain high dehydration membranes for an ethanol/water azeotrope, dried blend membranes prepared from mixtures of sodium alginate (Alg-Na) and sodium deoxyribonucleate (DNA-Na) were cross-linked by immersing in a methanol solution of CaCl2 or MaCl(2). In the dehydration of an ethanol/water azeotropic mixture by pervaporation, the effects of immersion time in methanol solution of CaCl2 or MaCl(2) on the permeation rate and water/ethanol selectivity through Alg-DNA/Ca2+ and Alg-DNA/Mg2+ cross-linked membranes were investigated. Alg-DNA/Mg2+ cross-linked membrane immersed for 12 h in methanol solution of MaCl(2) exhibited the highest water/ethanol selectivity. This results from depressed swelling of the membranes by formation of a cross-linked structure. However, excess immersion in solution containing cross-linker led to an increase in the hydrophobicity of cross-linked membrane. Therefore, the water/ethanol selectivity of Alg-DNA/Mg2+ cross-linked membranes with an excess immersion in cross-linking solution was lowered. The relationship between the structure of Alg-DNA/Ca2+ and Alg-DNA/Mg2+ cross-linked membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotropic mixture is discussed in detail.

• 出版日期2015-12-10