Polymer-modified nanofillers for enhancing CO2 separation performance of MMMs: A comparative study on the role of bridging ligands.

Advanced CO 2 separation technology is one of the key technologies for reducing carbon emissions and can make significant contributions to reducing the negative impact of the greenhouse effect on human survival. Membrane separation technology is regarded as a new generation of carbon capture technology because of its great potential to reduce carbon capture energy consumption and improve net carbon capture efficiency. Mixed matrix membranes (MMMs) can break through the performance limit of traditional polymer membranes, but the influence of bridging agents for post-modifying nanofillers on membrane structure and properties needs further systematic investigation. In this work, four types of ligands were selected for synthesizing polymer-modified nanofillers and then incorporated into poly (vinylamine) (PVAm) to prepare MMMs. The comparative analysis results indicate that bridging ligands with superior flexibility are conducive to enhancing the gas permeability within the pores by diminishing the compactness of the polymer shell. The constructed phase interface transition area with uniformly enhanced mechanical strength demonstrates the improved interface compatibility between the matrix and nanofillers bridged via the flexible ligand. Techno-economic evaluation verifies the industrial application potential of the optimal MMMs targeting CO 2 capture from post-combustion gas. Diagram of Nanofillers Structure Post-modified Using Polymer Homologous to the Matrix via Different Bridging Ligands. [Display omitted] • The properties of the polymer shell were regulated by bridging ligands with different flexibility. • Post-modification of nanofillers by homologous polymer generated excellent interfacial compatibility. • Ligands with strong flexibility stretched outer polymer to promote nanofillers' gas permselectivity. • The Maxwell model was conducted to verify the superiority of UIO- DEB -PVAm nanofillers. [ABSTRACT FROM AUTHOR]