characterization of commercial ceramic and hybrid membranes using gas permeation and permporometry tests

the gas separation performance of commercial ceramic titania and hybrid silica (hybsi®) membranes was assessed using the gas permeation and permporometry methods. results indicated that the hybsi® membranes have a hybrid surface containing regions covered by a polymeric matrix and others with inorganic pores. these membranes have high h2 selectivity, which increases significantly with temperature and after exposure to h2o vapors. on the other hand, titania membranes have a very narrow pore size distribution in the low mesoporous or in the upper microporous range. these membranes have very high permeance but moderate selectivity which is not affected by h2o exposure.