Application of organic-inorganic polymer hybrids as selective gas permeation membranes

Abstract

The gas permeability of polymer hybrid membranes has been investigated. The membranes were prepared by dip-coating a methanol solution of poly(N-vinylpyrrolidone) (PVP) and methyltrimethoxysilane (MTMOS) on porous glass tubes. The permeance was measured by using N ₂ , CO ₂ and He separately at a pressure of 1 kg cm ^–2 . It was found that the permeance of these gases all increased with temperature in the PVP hybrid membranes. In particular, the permeance of He increased at a much greater rate with temperature, resulting in high selectivity against N ₂ . For instance, the permeance of He is 150 times greater than that of N ₂ at 100 °C. The results indicate the dense structure of PVP hybrid membranes as confirmed by SEM observations. The hybrid membranes also exhibited high selectivity of CO ₂ against N ₂ . This could be attributed to the high polarity of amide groups in PVP chains which would facilitate the sorption of CO ₂ . These polymer hybrid membranes were also found to have high thermal stability compared to organic polymer membranes.