(278e) Molecularly Mixed Nanocomposite Membranes Based on High-Performance Commercial Polymer Blends for Efficientpre-Combustion CO2 Capture

Nanocomposite membrane materials with a good combination of attractive separation performance and potential commercial scalability are of pivotal role to realizing efficient pre-combustion CO₂ capture from syngas for producing clean hydrogen fuel. However, the utilization of nanoparticles in commercial polymeric membranes is still facing many incompatibility issues till now. Here, we report a novel nanocomposite membrane design based on a soluble organic macrocyclic cavitand, calix[6]arene (CA6), and polymer blends of commercial polyphenylsulfone (PPSU) and polybenzimidazole (PBI). The solubility in polymer solvents and good affinity for organic polymers allows CA6 to be able to homogeneously mix with the PPSU/PBI blends on a molecular basis. A series of PPSU/PBI blend based molecularly mixed composite membranes (MMCMs) are fabricated by the incorporating different amounts of CA6. The membranes achieve promising H₂/CO₂ separation performance owing to the effective size-sieving gas pathways through partially intruded CA6 cavities. 50%PPSU40-50%PBI-10%CA6 membrane achieved a 25% increase in H₂/CO₂ selectivity compared with the pristine 50%PPSU40-50%PBI membrane while the 50%PPSU40-50%PBI-15%CA6 membrane achieved a 35% increase in H₂/CO₂ selectivity compared with the pristine 50%PPSU40-50%PBI membrane. Also, the overall performance of both 50%PPSU40-50%PBI-10%CA6 and 50%PPSU40-50%PBI-15%CA6 can surpass the upper bound of H₂/CO₂ separation. This study could provide a new toolbox to design commercial polymer based nanocomposite membrane materials.