Novel organic-vycor glass composite membrane having Si-C bonds

A novel organic-ceramic membrane having stable Si-C bonds was developed for separation of high temperature organic solutions. Porous vycor glass was e mployed for a substrate which was modified by a series of chemical vapor de position (CVD) and hydrosilylation. 1,3,5,7-Tetramethylcyclotetrasiloxane ( 1-14) was used as a CVD source in order to introduce Si-H bonds on the surf ace of porous vycor glass. The Si-H bonds were then catalytically hydrosily lated with olefins. As a result, organic functional groups were introduced via Si-C bonds. A compact membrane was obtained when CVD treatment was carr ied out at 343 K. The membrane that was modified by the hydrosilylation of styrene showed benzene permselectivity in benzene/cyclohexane vapor permeat ion test at 373 K. The separation factor of benzene over cyclohexane was 2. 9 and benzene flux was 1.2 x 10(-8) mol m(-2)s(-1)Pa(-1), and the permeatio n properties are stable for more than 1000 min at 373 K.