Mixed-matrix membranes (MMMs) formed by incorporating metal-organic frameworks (MOFs) into polymers have ag eneral limitation in that the MOFs are typically formed into rather simple dimensionalities (such as 1D, 2D, or 3D). Each design approachh as intrinsic-albeit independent-benefits, such as network percolation (1D), access to high-aspect ratios (2D), and ease of processability (3D). However, ad esign strategyi s neededt oc ombine multiple dimensionalitiesa nd, thereby, access the full range of transport and compositingb enefits of these high-performance materials. Herein, af acile method to form multi-dimensional HKUST-1n anoparticles is introduced by using am odulator to tune the MOF nucleation and growth mechanism. At 30 wt %m ultidimensional MOF loading, the MMM shows CO 2 permeabilities of approximately 2500 Barrer, which represents a2 .5-fold increase compared to that of a pure polymer without al arge loss of selectivity for CO 2 /CH 4 and CO 2 /N 2 .A dditionally,a lmost no plasticization pressure response is observed for CO 2 up to 750 psi, suggesting an unusual stability to high activity feeds.[a] W.Supporting Information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Ethoxy substitution crosslinked and enhanced transport properties in novel ROMP and addition-type polynorbornenes for reverse-selectivity, heavy-hydrocarbon separations.

We demonstrate that the CO 2 /N 2 gas separation performance of alkoxysilyl-substituted vinyl-added polynorbornenes (VAPNBs) may be significantly enhanced via incorporation of the monomer 5-tris(2-methoxyethoxy)silyl-2-norbornene. As the molar ratio of this monomer is increased, substantial increases in CO 2 /N 2 selectivity are realized with minimal decrease in CO 2 permeability. This trend ignores the traditional permeability/selectivity "tradeoff" relationship and yields an optimal membrane whose performance reaches the 2008 upper bound for CO 2 /N 2 separations. Though the inclusion of 5-tris(2-methoxyethoxy)-silyl-2norbornene units was initially hypothesized to maximize CO 2 solubility, detailed gas sorption studies reveal that these highly glassy materials essentially lack any Langmuir sorption component and indicate that their improved CO 2 /N 2 selectivity is due to decreased N 2 solubility within the matrix. Computational modeling suggests that the source of this apparent "N 2 -phobicity" is likely explained through comparative analyses of polymer−polymer and polymer−gas interactions. Lastly, mixed-gas permeation tests are performed to provide a more realistic look at real-world gas separation performance.

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