Ryo Tamaki, Yoshiki Chujo, Koji Kuraoka and Tetsuo Yazawa
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 N2, CO2 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 N2. For instance, the permeance of He is 150 times greater than that of N2 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 CO2 against N2. This could be attributed to the high polarity of amide groups in PVP chains which would facilitate the sorption of CO2. These polymer hybrid membranes were also found to have high thermal stability compared to organic polymer membranes.