(551h) Enhanced Gas Separation Performance of Mixed-Linker Zeolitic Imidazolate Framework ZIF Membranes Via Post Synthetic Ligand Exchange
Properties of MOFs including gas transport properties are affected by structures of MOFs. To obtain MOFs with new properties, one can obtain via 1) direct (de novo) synthesis of new MOFs and 2) post-synthetic modifications (PSMs) of existing MOFs. PSMs include post-synthetic ligand and metal exchange5. Compared to the complex and sensitive nature of MOF formation process via de novo synthesis,6 PSMs are a simple and facile approach to impart new properties since daughter MOFs with new properties can be obtained without compromising the structures of mother MOFs. Recent studies have shown that PSMs can modify pore size and surface properties, thereby separation performances.7-9
In this talk, we would like to present improved gas separation performances of ZIF-8 membranes via post-synthetic ligand exchange by systematically reducing the effective aperture size of ZIF-8. Mother ZIF-8 membranes prepared by a secondary growth were subjected to post-synthetic linker exchange with ZIF-7 linkers, i.e., benzimidazole. The effects of the PSM on the gas separation performance and water stability of the modified membranes will be discussed.
1 Park KS, Ni Z, CÃ´tÃ© AP, et al., (2006) âExceptional chemical and thermal stability of zeolitic imidazolate frameworksâ, Proceedings of the National Academy of Sciences, 103 (27), pp 10186-10191
2 Thompson, J. A., Blad, C. R., Brunelli, N. A., Lydon, M. E., Lively, R. P., Jones, C. W., Nair, S., âHybrid Zeolitic Imidazolate Frameworks: Controlling Framework Porosity and Functionality by Mixed-Linker Synthesisâ, Chemistry of Materials, 2012, 24 (10), pp 1930â1936
3 Zhang C, Lively RP, Zhang K, Johnson JR, Karvan O, Koros WJ., (2012) âUnexpected Molecular Sieving Properties of Zeolitic Imidazolate Framework-8â, The Journal of Physical Chemistry Letters., 3 (16), pp 2130-2134.
4 YanâShuo Li., YS., Liang, FY., Bux, H., Feldhoff, A., Yang, WS., Caro, J., âMolecular Sieve Membrane: Supported MetalâOrganic Framework with High Hydrogen Selectivityâ, Angewandte Chemie International Edition., 2010, 122, pp 558-561
5 Tanabe, KK. and Cohen, SM., (2011), âPostsynthetic modification of metal-organic frameworks-a progress reportâ, Chemical Society Reviews, 40 (2), pp 498-519.
6 Kim, M., Cahill, JF., Fei, H., Prather, KA., and Cohen, SM., (2012) âPostsynthetic Ligand and Cation Exchange in Robust MetalâOrganic Frameworksâ, Journal of the American Chemical Society, 134 (43), pp 18082-18088
7 Lee, M. J., Kwon, H. T., Jeong, HK., âHighâFlux Zeolitic Imidazolate Framework Membranes for Propylene/Propane Separation by Postsynthetic Linker Exchangeâ, Angewandte Chemie International Edition, 2018, 57, pp 156-161
8 Karagiaridi, O., Lalonde, M. B., Bury, W., Sarjeant, A. A., Farha, O. M., Hupp, J. T., âOpening ZIF-8: A Catalytically Active Zeolitic Imidazolate Framework of Sodalite Topology with Unsubstituted Linkersâ, Journal of the American Chemical Society, 2012, 134 (45), pp 18790-18796
9 Zhang, H., James, J., Zhao, M., Yao, Y., Zhang, Y., Zhang, B., Lin, Y.S., âImproving hydrostability of ZIF-8 membranes via surface ligand exchangeâ, Journal of Membrane Science, 2017, 532, pp 1-8