Nanofluidic Behavior at the Fluid-Solid Interface

Abstract

The confinement and nature of complexity at the fluid-solid interface pose significant challenges for studying the nanofluidic behavior. Here, we report an approach to probe the rheological performance of three media through dynamic interaction with a harmonic oscillator. A prototype device is developed that is able to vibrate in the range up to hundreds of hertz. Results show that the interfacial viscosity was similar to that of its bulk in terms of amplitude and frequency. However, an additional phase lag appeared when the amplitude was small, and its responsive curve exhibited distortion around the natural frequency. Theoretical analysis indicated that this might be due to fluid memory because the fluid response to the solid motion is not instantaneous. The approach reported here has potential to lead toward new ways of studying dynamic properties of fluid-solid interfaces.

A continuum model to study fluid dynamics within oscillating elastic nanotubes

“…The possibility of generating high-frequency flows, predicted by our model, opens up a panorama to control and explore pulsatile flow in the range of the molecular time scales (Pit, Hervet & Léger 2000;Zhu & Granick 2001;Chen et al 2019;Zhao et al 2020a). This would enable us to study, for instance, the molecular causes of flow slippage at the tube/fluid interface, since the detachment of a molecule from the pinning point in the wall surface has been predicted to occur at shear rates of the order of GHz and higher (Thompson & Troian 1997;Zhang et al 2019;Zhao, Wei & Yuan 2020b).…”

“…The possibility of generating high-frequency flows, predicted by our model, opens up a panorama to control and explore pulsatile flow in the range of the molecular time scales (Pit, Hervet & Léger 2000; Zhu & Granick 2001; Chen et al. 2019; Zhao et al. 2020 a ).…”