CO2-philic mixed matrix membranes based on low-molecular-weight polyethylene glycol and porous organic polymers

Membrane-based separation processes can efficiently capture CO2 and reduce energy consumption. However, the synthesis of a CO2-philic material which can replace traditional gas separation materials for advanced membrane separation faces numerous challenges. In this paper, we report the incorporation of porous organic polymers (POPs) and low-molecular-weight polyethylene glycol (PEG 400) into Pebax 1657 for the fabrication of a CO2- philic mixed matrix membrane for CO2 capture. The POPs, which contained azo bonds and phenolic hydroxyl groups, exhibited CO2-philic and N-2-phobic properties. PEG 400, which possesses ethylene oxide (EO) units with a polar ether group, enhanced the CO2 permeability and CO2/N-2 selectivity. This CO2-philic membrane showed CO2 permeability of 392 Barrer and CO2/N-2 selectivity of 112, which surpassed the upper bound (2019). This membrane could be a widely applicable tool for improving CO2 capture with advanced membranes.

Automated summary

The study successfully synthesized a CO2-philic mixed matrix membrane by incorporating POPs and PEG 400 into Pebax 1657, improving the efficiency and selectivity of CO2 capture. This membrane showed excellent performance in terms of CO2 permeability and CO2/N-2 selectivity, surpassing the upper limit set in 2019, and has the potential to be a key tool in advanced membrane technology for CO2 capture.