Development of robust polysesquioxane/polymer dual-network hybrid membranes for flue gas carbon capture

In the present study, robust organic/inorganic dual-network membranes were designed by combining the advantages of polysesquioxane with superior thermal and structural stabilities, and polyether with outstanding CO₂-philic and film-forming abilities. Specifically, a typical polysesquioxane precursor, bis(triethoxysilyl)ethane (BTESE), was selected to generate the inorganic-based amorphous network via a hydrolysis and condensation process, during which polyethylene glycol (PEG) was introduced to form the organic network. The Si-O-Si network derived from BTESE could provide excellent mechanical stability, while the repeat polar ethylene oxide units contained in PEG were expected to furnish a strong affinity toward CO₂ through dipolar-dipolar interactions. In comparison to individual membranes, the dual-network membranes presented both attractive CO₂/N₂ separation performance and improved structural stability. These dual-network membranes proposed in this work hold great potential in industrial flue gas carbon capture and the strategies for designing such inorganic–organic dual-network membranes could be extended to other robust inorganic–organic hybrid films/materials.