(705c) Facile Defect Engineering of Zeolitic Imidazolate Frameworks Towards Enhanced Propylene/Propane Separation Performance

Mixed matrix membranes (MMMs) are hybrid membranes consisting of molecular sieves and polymeric membranes for dual advantages of good separation performance and processability. However, several challenging issues still remain prior to commercialization of MMMs, including engineering of pore structures of molecular sieves and interfacial voids between polymer and molecular sieves. In this presentation, I will report highly processable zeolitic imidazolate framework-8 (ZIF-8) nanoparticles for enhanced propylene/propane separation performance by facile defect engineering [1]. The addition of amine modulators under the suppressed nuclei concentrations allows the formation of new Zn-alkyl amine (Zn-AA) point defects in the resultant ZIF-8 nanoparticles, but restrains the formation of typical Zn-OH point defects by fast coordination reaction. Our Zn-AA defective ZIF-8s exhibit a more restricted flipping motion of the ligands, and thus, possess a higher framework rigidity. Furthermore, partially coordinated amine modulators successfully enhance the interfacial interaction between various engineering polymers and ZIFs, enabling accommodation of high ZIF concentrations in MMMs as well as excellent propylene/propane separation performance.

[1] H. An et al., Adv. Funct. Mater., 2021, 31, 2105577.