Gao Meizhen, Wang Jing, Rong Zhenghao, Shi Qi, Dong Jinxiang
Research Institute of Special Chemicals, College of Chemistry and Chemical Engineering, Taiyuan University of Technology Taiyuan 030024 China
RSC Adv. 2018 Nov 27;8(69):39627-39634. doi: 10.1039/c8ra08460b. eCollection 2018 Nov 23.
We synthesized a series of seven zeolitic imidazolate frameworks (ZIFs), namely ZIF-8, ZIF-90, SIM-1, MAF-6, ZIF-25, ZIF-93 and ZIF-97. Then we investigated the adsorption behavior of water for each ZIF a combined experimental-computational method. We focused on the van der Waals (vdW) and electrostatic contributions to their water adsorption capacity. The results showed that the vdW interactions were negligible and that electrostatic interactions played a dominant role. Moreover, we studied the effects of topology in the [Zn(almeIm)] system with the same linker, 4-methylimidazole-5-carbaldehyde (almeIm). We found that SIM-1 with a smaller pore size and higher density exhibited greater water adsorption at low relative pressures, and in contrast, ZIF-93 with a larger pore size and lower density had significantly higher adsorption capacity at high relative pressures.
我们合成了一系列七种沸石咪唑酯骨架材料(ZIFs),即ZIF-8、ZIF-90、SIM-1、MAF-6、ZIF-25、ZIF-93和ZIF-97。然后我们采用实验与计算相结合的方法研究了每种ZIF对水的吸附行为。我们重点研究了范德华(vdW)力和静电作用对其水吸附能力的贡献。结果表明,范德华相互作用可忽略不计,静电相互作用起主导作用。此外,我们研究了在具有相同连接体4-甲基咪唑-5-甲醛(almeIm)的[Zn(almeIm)]体系中拓扑结构的影响。我们发现,孔径较小且密度较高的SIM-1在低相对压力下表现出更大的水吸附量,相反,孔径较大且密度较低的ZIF-93在高相对压力下具有显著更高的吸附容量。