Institute of Chemistry , University of Silesia , Szkolna 9 , 40-006 Katowice , Poland.
Laboratory of Thermomolecular Energetics , National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" , Pr. Peremogy 37 , 03056 Kyiv , Ukraine.
ACS Appl Mater Interfaces. 2019 Oct 30;11(43):40842-40849. doi: 10.1021/acsami.9b14031. Epub 2019 Oct 15.
In this article, the effect of a porous material's flexibility on the dynamic reversibility of a nonwetting liquid intrusion was explored experimentally. For this purpose, high-pressure water intrusion together with high-pressure in situ small-angle neutron scattering were applied for superhydrophobic grafted silica and two metal-organic frameworks (MOFs) with different flexibility [ZIF-8 and Cu(tebpz) (tebpz = 3,3',5,5'tetraethyl-4,4'-bipyrazolate)]. These results established the relation between the pressurization rate, water intrusion-extrusion hysteresis, and porous materials' flexibility. It was demonstrated that the dynamic hysteresis of water intrusion into superhydrophobic nanopores can be controlled by the flexibility of a porous material. This opens a new area of applications for flexible MOFs, namely, a smart pressure-transmitting fluid, capable of dissipating undesired vibrations depending on their frequency. Finally, nanotriboelectric experiments were conducted and the results showed that a porous material's topology is important for electricity generation while not affecting the dynamic hysteresis at any speed.
本文通过实验探索了多孔材料的柔韧性对非润湿液体侵入的动力学可逆性的影响。为此，采用高压水侵入和高压原位小角中子散射技术，研究了具有不同柔韧性的超疏水接枝二氧化硅和两种金属有机骨架（MOFs）[ZIF-8 和 Cu(tebpz)（tebpz = 3,3',5,5'-四乙基-4,4'-联吡啶）]。这些结果建立了加压率、水侵入-挤出滞后与多孔材料柔韧性之间的关系。研究表明，通过控制多孔材料的柔韧性，可以控制超疏水纳米孔中水侵入的动态滞后。这为柔性 MOFs 开辟了一个新的应用领域，即一种智能压力传递流体，能够根据频率消散不需要的振动。最后，进行了纳微摩擦电实验，结果表明，多孔材料的拓扑结构对发电很重要，而在任何速度下都不会影响动态滞后。
