Separation and Purification Technology, Vol.169, 223-229, 2016
Coupled-PDMS grafted mesoporous gamma-alumina membranes for solvent nanofiltration
In this paper grafting of mesoporous gamma-alumina membranes with hydride terminated polydimethylsiloxane is described. Vinyltriethoxysilane is used as linking agent and tetrakis(vinyldimethylsiloxy)silane as a coupling agent, to create a dense network structure that is grafted in the ceramic pores. Grafting performance of the organic moieties on gamma-alumina powders was analyzed by FTIR and TGA. The results indicate that grafting reactions were successfully carried out. Contact angle analysis on the grafted membranes showed that grafting occurs on the gamma-alumina layer and that the resulting membrane surface had a water contact angle of 108 degrees. From permeability and rejection tests using Sudan Black in toluene, ethyl acetate or isopropanol, the use of a coupling agent was found to result in a more dense network structure grafted in the gamma alumina pores. This resulted in a higher rejection for nanofiltration of solvents but at the cost of a lower solvent permeability, when compared with PDMS-grafted alumina membranes where no coupling of PDMS was applied. (C) 2016 Elsevier B.V. All rights reserved.