High nanoparticles loadings mixed matrix membranes via chemical bridging-crosslinking for CO2 separation

Abstract

Under high nanoparticles loadings, the gas separation performance mixed matrix membranes (MMMs) could be limited by the inferior compatibility between polymer and nanoparticles. Herein, we utilized a “bridging-crosslinking” method to connect the polymer and nanoparticles via macromolecule. Specially, the poly(vinylamine) (PVAm) and UIO-66-NH2 nanoparticles were bridging-crosslinked by using poly(ethylene glycol) diglycidyl ether (PEGDE) to achieve high nanoparticles loadings. By this way, even though the nanoparticles loadings attained 28.5 wt%, the incorporated nanoparticles still showed good dispersion in coating solution without sedimentation for one week. According to the gas permeation test, the fabricated MMMs with amounts of functional groups via “bridging-crosslinking” method displayed excellent gas separation performance and good long-term stability under the simulated flue gas. For CO2/N2 (15/85) mixed gas, the MMMs can achieve a high CO2 permeance of 1295 GPU and CO2/ N2 selectivity of 91 at 0.3 MPa. For CO2/CH4 (10/90) mixed gas and CO2/H2 (40/60) mixed gas, the gas separation performance of MMMs was investigated.