Nanoporous carbon membrane for CO₂ separation

Abstract

Polybenzoxazine xerogel membrane for gas separation was prepared via sol-gel synthesis and cost-effective ambient drying. After pyrolysis at 800 °C under nitrogen atmosphere, carbon xerogel was obtained. The Brunauer, Emmett, Teller (BET) surface area of the carbon xerogel membrane was approximately 360 m2/g. Activation of the carbon xerogels under CO2 atmosphere and thermal treatment at 900 °C was also investigated in order to compare gas separation performance. The BET surface area of the CO2 activated carbon xerogels increased approximately 2 times in comparison to the unactivated porous carbon film. On the other hand, the BET surface area of the heat-treated carbon xerogel film decreased to 110 m2/g due to the re-alignment of the pore structure of carbon. The gas separation measurement showed that polybenzoxazine-derived carbon xerogel exhibited good gas separation performance. It was also found that the gas separation selectivity could be modified by varying the surface treatment of the resulting porous carbon