ACS applied materials & interfaces | 2019
Effect of flexibility and nanotriboelectrification on the dynamic reversibility of water intrusion into nanopores: Pressure transmitting fluid with frequency-dependent dissipation capability.
Abstract
In this article the effect of a porous material´s flexibility on the dynamic reversibility of a non-wetting 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 Cu2(tebpz) (tebpz = 3,3 ,5,5 tetraethyl-4,4 -bipyrazolate)). These results established the relation between pressuri-zation 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 fre-quency. 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.