Enhanced selectivity in mixed matrix membranes for CO2 capture through efficient dispersion of amine-functionalized MOF nanoparticles


Mixed matrix membranes (MMMs) for gas separation applications have enhanced selectivity when compared with the pure polymer matrix, but are commonly reported with low intrinsic permeability, which has major cost implications for implementation of membrane technologies in large-scale carbon capture projects. High-permeability polymers rarely generate sufficient selectivity for energy-efficient CO2 capture. Here we report substantial selectivity enhancements within high-permeability polymers as a result of the efficient dispersion of amine-functionalized, nanosized metal–organic framework (MOF) additives. The enhancement effects under optimal mixing conditions occur with minimal loss in overall permeability. Nanosizing of the MOF enhances its dispersion within the polymer matrix to minimize non-selective microvoid formation around the particles. Amination of such MOFs increases their interaction with thepolymer matrix, resulting in a measured rigidification and enhanced selectivity of the overall composite. The optimal MOF MMM performance was verified in three different polymer systems, and also over pressure and temperature ranges suitable for carbon capture.

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Figure 1: Fabrication of MMMs in this study.
Figure 2: MOF and MMM physical characterization.
Figure 3: Computational studies of adhesions between PIM-1 and UiO-66 particles.
Figure 4: Gas transport properties.
Figure 5: Mechanical studies of PIM-1 MMMs and demonstration of similar performance in other polymer MMMs.


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H.H. thanks JST-PRESTO (JPMJPR141B) and City University of Hong Kong for financial support. E.S. gratefully acknowledges JST-PRESTO (JPMJPR1417) and the Japanese Ministry of Environment as part of the project ‘Low Carbon Technology Research, Development and Demonstration Program’. iCeMS is supported by the World Premier International Research Initiative (WPI), MEXT, Japan.

Author information




B.G. conceived and designed the research. K.S. and Y.K. synthesized and analysed PIM-1 MMMs, K.W. synthesized and analysed PEBAX MMMs, A.P. synthesized and analysed polyurethane MMMs, S.F. and S.K. evaluated MOF-related data, Q.S. evaluated mixed membrane data, K.D. and H.H. performed simulations and H.K. S.K. and E.S. supervised researchers in the project. All authors discussed the results and commented on the manuscript at all stages.

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Correspondence to Easan Sivaniah.

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Ghalei, B., Sakurai, K., Kinoshita, Y. et al. Enhanced selectivity in mixed matrix membranes for CO2 capture through efficient dispersion of amine-functionalized MOF nanoparticles. Nat Energy 2, 17086 (2017). https://doi.org/10.1038/nenergy.2017.86

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