High-performance CO2/CH4 separation membrane fabrication with PVAm modified by the MOFs containing amine groups

Abstract The polyvinylamine (PVAm) was respectively modified by the MOFs (IRMOF-3 and ZIF-8) with amine groups that were characterized by TEM, SEM and XRD. The PVAm-MOFs/polysulfone (mPSf) mixed matrix membranes (MMMs) were fabricated by coating different PVAm-MOFs mixtures on mPSf ultrafiltration membranes. The performance of the PVAm-MOFs/mPSf and PVAm/mPSf membranes for CO2/CH4 separation was investigated. Compared with the PVAm/mPSf virgin membrane, PVAm-MOFs/mPSf MMMs display higher CO2 separation performance due to the decreased membrane effective thickness and incorporation of amine-rich nanochannels. Furthermore, compared with PVAm-ZIF-8/mPSf MMMs, the PVAm-IRMOF-3/mPSf MMMs possess higher CO2/CH4 separation performance. Then the CO2/CH4 separation performance of the PVAm-IRMOF-3/mPSf MMMs with different IRMOF-3 loadings was studied. Compared with other reported membranes, the PVAm-IRMOF-3/mPSf MMM loaded 25 wt% IRMOF-3 shows higher CO2/CH4 separation performance at both low and high feed pressure.