Modulation of the Polyamide Microstructure by Multidimensional Fillers for CO₂ Separation from Flue Gas

Rational regulation of the polyamide (PA) membrane microstructure is vital for the CO2 separation performance. However, the dense network structure and insufficient number of CO2-philic groups limit the conventional PA membranes from having both excellent CO2 permeability and excellent CO2/N2 selectivity. Herein, the multidimensional fillers (BN-LDH and LDH) are intentionally constructed to modulate the PA membranes for CO2 separation performance. 3D BN-LDH fillers would effectively regulate the microstructure of the PA and also extremely enhance the content of polar groups, thereby optimizing the CO2 separation performance of the PA composite membranes. The optimized membrane exhibits remarkable increases in CO2 permeability and CO2/N2 selectivity, which are 6.3- and 5.7-fold higher than those of the pure PA membrane, respectively. This work provides a facile and effective strategy to regulate PA membranes to study the CO2 separation performance and can be expanded to other multidimensional group-rich materials.