Preparation and characteristics of functionalized multiwalled carbon nanotubes in polyimide mixed matrix membrane

Abstract

The functionalization of multiwalled carbon nanotubes (MWNTs) with ß cyclodextrin (ß-CD) is described. The functionalization using ß-CD treatment is an environmentally friendly and nondestructive method to modify carbon nanotubes. It was observed that the degree of functionalization increases with increasing ratios of ß-CD as seen from the Raman analysis. The Raman spectra also indicated that the nanotubes walls were not damaged. The presence of functional groups associated with ß-CD on the functionalized MWNTs indicated that the cyclodextrin groups were found to be adsorbed at the surface of the nanotubes walls. Mixed matrix membrane (MMM) was prepared by a phase inversion process. Enhanced selectivity and permeability for CO2 over CH4 was observed for MMM prepared using functionalized MWNTs.