Co-fa Nanoplates Incorporated 6FDA-DAM Mixed-Matrix Membranes for Enhanced CO2/CH4 Separation

Plate-like or sheet-like porous materials with nanometer thickness have been considered as the preferred fillers to improve mixed-matrix membranes (MMMs)-based separation. Herein, hexagonal Co-fa (HG-Co-fa) nanoplates were simply synthesized without the addition of any modifier and used as fillers to construct 6FDA-DAM-based MMMs for efficient CO2/CH4 separation. HG-Co-fa nanoplates exhibit high dispersion and interface compatibility in 6FDA-DAM matrix. The results demonstrated that the CO2/CH4 separation performance of 6FDA-DAM was obviously improved after the incorporation of HG-Co-fa nanoplates. The resultant MMMs with nanoplate loading of 10 wt% showed CO2/CH4 selectivity of 27 and CO2 permeability of 1419 Barrer at 25 degree celsius and 0.2 MPa, surpassing 2008 Robeson upper bound. Meanwhile, the high lattice integrity and structural stability of HG-Co-fa nanoplates contribute to the excellent thermal and mechanical stability of MMMs, contributing to their antiplasticization property up to 14 bar and long-term stability up to 240 h, indicating their potential for natural gas separation.