CO2 removal using membrane gas absorption with PVDF membrane incorporated with POSS and SAPO-34 zeolite

Abstract

The mixed matrix membranes designed with enhanced affinity for CO2 by incorporating the gas selective fillers are studied in this work. Polyhedral oligomeric silsesquioxane (POSS) and SAPO-34 zeolite were selected to engineer the additional pathway for CO2 diffusion in polyvinylidenefluoride (PVDF) membrane in order to improve the CO2 removal via membrane gas absorption (MGA). The double-soft coagulation resulted in the neat PVDF membrane (M-0) with a mean pore size of 2.77±0.09μm and a water contact angle of 137.5°. M-S34 membrane with the hydrophilic SAPO-34 zeolite and M-AP membrane with aminopropylisobutyl POSS exhibited the smaller pore size and lower water contact angle than the neat membrane. Although the mean pore size of M-SP membrane with trisilanolisobutyl POSS (0.54±0.06μm) is small in comparison to M-0 membrane, it showed the similar water contact angle of 132.4 ° to M-0 membrane. The reduction of pore size could be related to the fast coagulation caused by different interactions between polymer, filler, solvents and non-solvents. Nevertheless, the blending of trisilanolisobutyl POSS into M-SP membrane still improved the CO2 absorption flux which is more than 2 times higher than the neat membrane. The functionality of SAPO-34 and aminopropylisobutyl POSS in the PVDF membranes was limited by the low pressure and membrane morphology, respectively.