High CO2 separation performance of Pebax®/CNTs/GTA mixed matrix membranes

Abstract Pebax ® /CNTs (MWNTs, MWNTs-OH and MWNTs-NH 2 ) and Pebax ® /MWNTs-NH 2 /GTA mixed matrix membranes (MMMs) were prepared with solution-casting method. First, the effect of CNTs functionalization on the properties of Pebax ® /CNTs MMMs was studied. The functionalization of CNTs promoted their dispersion in Pebax ® matrix. The gas permeabilities of Pebax ® /CNTs MMMs were enhanced with the addition of CNTs. And, the enhancement of gas permeabilities induced by CNTs was in the order of MWNTs-NH 2 >MWNTs-OH>MWNTs. Then, Pebax ® /MWNTs-NH 2 MMMs were chosen to be further modified with GTA. GTA promoted the dispersion of MWNTs-NH 2 in Pebax ® matrix, and it acted as a plasticizer and increased the chain mobility of Pebax ® as well as the FFV of Pebax ® /MWNTs-NH 2 /GTA MMMs. The gas diffusion coefficients and solubility coefficients all increased with the increase of GTA content. Consequently, the gas permeabilities of Pebax ® /MWNTs-NH 2 /GTA MMMs remarkably increased with the increase of GTA content. CO 2 permeabililty of P10C N 1G25 was higher than pristine Pebax ® and P10C N 1G0 by almost ten times and six times, respectively. CO 2 /light gas separation performance of Pebax ® was significantly enhanced by CNTs and GTA.