Metallic copper incorporated ionic liquids toward maximizing CO2 separation properties

Abstract

We report the facilitated CO2 transport membrane by in situ preparation of copper nanoparticles by ionic liquid, such as HmimNO(3). The dissociation mechanism of micro-sized copper flakes into surface activated copper nanoparticles in terms of the interface dipole at the organic/metal was suggested. Firstly, HmimNO(3) adsorbed onto pristine micro-sized copper flakes consisted of clusters, and then the concentration of electrons in the NO3- lead to the positive charging of the vacuum side. The built-in potential at the interface of HmimNO(3)/Cu clusters was able to bring out the repulsive force among the positive charged Cu clusters, resulting in the formation of CuNPs. Furthermore, the fabricated Cu nanoparticles (CuNPs) could be utilized as not only CO2 carriers, but also barriers regarding N-2 and CH4 transport. The ideal CO2/CH4 and CO2/N-2 separation factor of HmimNO(3) membranes with a polysulfone asymmetric support was 2.3 and 2.6, respectively. The HmimNO(3)/CuNPs nanocomposite showed selectivity for CO2/CH4 and CO2/N2 was found to be 6.2 and 7.4, respectively. This implied the surface positive polarized CuNPs addition could be one of the effective strategies toward maximizing CO2 separation. (C) 2013 Elsevier B.V. All rights reserved.