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: Tadashi Uragami, Takuya Katayama, Takashi Miyata, Hiroshi Tamura, Tadashi Shiraiwa, Akon Higuchi
• Journal: Biomacromolecules (Biomacromolecules) 2004 Jul-Aug Vol. 5 Issue 4 Pg. 1567-74 ISSN: 1525-7797 [Print] United States
• PMID: 15244479 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Membranes, Artificial
• Silanes
• Water
• Ethanol
• tetraethoxysilane
• Chitosan

Topics

• Carbohydrate Sequence
• Chitosan (chemical synthesis, chemistry)
• Desiccation (methods)
• Ethanol (chemistry)
• Membranes, Artificial
• Molecular Sequence Data
• Silanes (chemistry)
• Water (chemistry)