title: Dehydration of an ethanol/water azeotrope by novel organic-inorganic hybrid membranes based on quaternized chitosan and tetraethoxysilane.
abstract: To control swelling of quaternized chitosan (q-Chito) membranes, mixtures of q-Chito as an organic component and tetraethoxysilane (TEOS) as an inorganic component were prepared using the sol-gel reaction, and novel q-Chito/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation, the effect of TEOS content on the water/ethanol selectivity of q-Chito/TEOS hybrid membranes was investigated. Hybrid membranes containing up to 45 mol % TEOS exhibited higher water/ethanol selectivity than the q-Chito membrane. This resulted from depressed swelling of the membranes by formation of a cross-linked structure. However, introduction of excess TEOS led to greater swelling of the hybrid membranes. Therefore, the water/ethanol selectivity of the hybrid membranes containing more than 45 mol % TEOS was lower than that of the q-Chito membrane. The relationship between the structure of q-Chito/TEOS hybrid membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotrope is discussed in detail.
authors.affiliation: Faculty of Engineering and High Technology Research Center, Kansai University, Suita, Osaka 564-8680, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Uragami
authors.forename: Takuya
authors.initials: T
authors.lastname: Katayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tamura
authors.forename: Tadashi
authors.initials: T
authors.lastname: Shiraiwa
authors.forename: Akon
authors.initials: A
authors.lastname: Higuchi
mesh_terms: D002240:Carbohydrate Sequence; D048271:Chitosan / Q000138:chemical synthesis / Q000737:chemistry*; D003890:Desiccation / Q000379:methods*; D000431:Ethanol / Q000737:chemistry*; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D012821:Silanes / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D012821:Silanes; D014867:Water; D000431:Ethanol; C040733:tetraethoxysilane; D048271:Chitosan