Tin, P.S and Chung, T.S and Dai, Y. and Guiver, M.D. Novelapproaches to fabricate carbon membranes based on chemical modified and solvent treated polymides. In: Proceedings of Regional Symposium on Membrane Science and Technology 2004, 21-25 April 2004, Puteri Pan Pacific Hotel, Johor Bharu, Malaysia.
PDF (Full Text)
Two brand-new modification technologies were developed for pyrolyzing the carbon molecular sieve membranes (CMSMs) with excellent separation efficiency. It is believed that the space filling effect by these modifications could considerably alter the separation performance of resultant carbon membranes. Firstly, a cross-linking modification was performed on polymeric precursors at room temperature before pyrolysis. The effectiveness of chemical cross-linking technology in improving gas separation capability of CMSMs was investigated. Results demonstrated that the permeability of modified CMSMs decreased with increasing in cross-linking density. Detailed examination reveals that cross-linking modification increased the selectivity at a low cross-linking but reduced the selectivity at a higher degree of cross-linking. The improvement of separation efficiency at low degree of cross-linking is presumably related to the swelling of polymer chains by methanol during cross-linking modification. Consequently, the second extremely simple modification method by using pure methanol immersion was developed. It was found that the CMSMs derived from methanol-treated precursors exhibited superior transport properties. Methanol treatment yielded CMSMs with higher selectivities if compared to CMSMs based on untreated and cross-linked Matrimid. Therefore, it can conclude that the swelling of polymer chains by methanol appears to be an effectual modification method to produce the CMSMs with excellent separation properties.
|Item Type:||Conference or Workshop Item (Paper)|
|Uncontrolled Keywords:||Carbon membranes, gas separation, chemical modification, cross-linking, polyimide precursors.|
|Subjects:||T Technology > TP Chemical technology|
|Divisions:||Chemical and Natural Resources Engineering (Formerly known)|
|Deposited By:||Pn Norazana Ibrahim|
|Deposited On:||23 Feb 2007 10:11|
|Last Modified:||01 Jun 2010 02:50|
Repository Staff Only: item control page