Carbon Nanotube Incorporated Nanocomposite Membranes for CO_2 Removal

Thin-film nanocomposite (TFN) membranes that consist of multi-walled carbon nanotube (MWNT) incorporated polyamide selective layer formed on polysulfone substrate were developed. The resultant TFN membranes were used for CO_2 gas removal. For inclusion into these active layers, a grafting procedure for CNT was established in this study to enhance their hydrophobicity. MWNTs grafted with poly (methyl methacrylate) (PMMA) were synthesized via a micro emulsion polymerization of methyl methacrylate (MMA) in the presence of acid-modified multi-walled carbon nanotubes (c-MWNTs). Subsequently, polyamide TFN membranes containing PMMA–MWNTs were prepared via interfacial polymerization reaction between aqueous and organic phases. The resultants TFN were characterized by using FTIR and SEM. Morphology studies demonstrate that MWNTs have been successfully embedded into the active polyamide layer. The gas selectivity increased about 6.6 times compared to the thin-film composite membrane when using 0.35 w/v% amine in the aqueous phase, 0.28 w/v% trimesoyl chloride (TMC) in organic phase and 0.50g/L PMMA–MWNTs in coating layer.