The comprehensive elastic properties of Zeolitic Imidazolate Frameworks (ZIF-1 to ZIF-4) have been computed using density functional theory (DFT). We employed the periodic CRYSTAL14 code to calculate the single-crystal elastic coefficients (Cij) at the B3LYP level of theory. While the chemical compositions of ZIFs-1 to -4 are the same, each structure features a distinct network topology, crysta...

Zn(2-methylimidazole)2 (ZIF-8), as one of the most important metal-organic framework (MOF) molecules, is a promising candidate for drug delivery due to its low-density structure, high surface area, and tunable frameworks. However, ZIF-8 exhibits a high cytotoxicity associated with its external hydrophobic surface, which significantly restricts its application in drug delivery and other biomedic...

Using neutron inelastic scattering and diffraction, we have studied the quantum methyl rotation in zeolitic imidazolate framework-8 (ZIF-8: Zn(MeIM)(2), MeIM = 2-methylimidazolate). The rotational potential for the CH(3) groups in ZIF-8 is shown to be primarily 3-fold in character. The ground-state tunneling transitions at 1.4 K of 334 +/- 1 mueV for CH(3) groups in hydrogenated ZIF-8 (H-ZIF-8)...

Zeolitic imidazolate frameworks (ZIFs) 7 and 9 are excellent candidates for CO2 adsorption and storage. Here, high-pressure X-ray diffraction is used to further understand their potential in realistic industrial applications. ZIF-7 and ZIF-9 are shown be able to withstand high hydrostatic pressures whilst retaining their porosity and structural integrity through a new ferroelastic phase transit...

Metal-organic framework (MOF) membranes have received increasing attention as adsorbents, yet the defects in most membrane structures greatly thwart their capacity performance. In this work, we fabricated a novel ZnO/2-methylimidazole nanocomposite with multiple morphology by electrochemical method. The nanocomposite provided sufficient and strong anchorages for the zeolitic imidazolate framewo...

Currently, finding high capacity adsorbents with large selectivity to capture Xe is still a great challenge. In this work, nitrogen-doped porous carbons were prepared by programmable temperature carbonization of zeolitic imidazolate framework-8 (ZIF-8) and ZIF-8/xylitol composite precursors and the resultant samples are marked as Carbon-Z and Carbon-ZX, respectively. Further adsorption measurem...

The deformation and mechanical behavior of individual zeolitic-imidazolate framework (ZIF-8) micro- and sub-microcrystals were observed under compression. Young's modulus and volume changes as a function of applied pressure were determined on individual single crystals, offering insights in the relationship among structure, morphology, and mechanical properties. Dramatic volume decreases and am...

A hierarchical zeolitic imidazolate framework-8 (micro/meso-ZIF-8) was fabricated by using cetyltrimethylammonium bromide as a structure-controlling agent and l-histidine as co-templates. Compared to the conventional microporous ZIF-8 (micro-ZIF-8), the hierarchical porous structure of micro/meso-ZIF-8 contains micropores and maximum mesopores of around 35.6 nm. The as-prepared hierarchical mic...

Separation of low boiling gas mixtures is widely concerned in process industries. Now their separations heavily rely upon energy-intensive cryogenic processes. Here, we report a pseudo-absorption process for separating low boiling gas mixtures near normal temperature. In this process, absorption-membrane-adsorption is integrated by suspending suitable porous ZIF material in suitable solvent and...

NMR relaxation studies and spectroscopic measurements of zeolitic imidazolate framework-8 (ZIF-8) are reported. The dominant nuclear spin−lattice relaxation (T1) mechanism for ZIF-8 in air arises from atmospheric paramagnetic molecular oxygen. The C T1 measurements indicate that the oxygen interacts primarily with the imidazolate ring rather than the methyl substituent. Similar relaxation behav...