Water Slippage on Graphitic and Metallic Surfaces: Impact of the Surface Packing Structure and Electron Density Tail

• Published in: Journal of physical chemistry. C Vol. 124; no. 21; pp. 11392 - 11400
• Main Authors: Cho, Kang Jin, Gim, Suji, Lim, Hyung-Kyu, Kim, Changho, Kim, Hyungjun
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.05.2020
• Subjects: adhesion; hydrodynamics; physical chemistry; tail
• ISSN: 1932-7447; 1932-7455; 1932-7455
• DOI: 10.1021/acs.jpcc.0c00854

While fluid flow at solid–liquid interfaces has been of great interest, studying its behavior is challenging because it requires a comprehensive understanding of the complex interactions that exist at various realistic solid–liquid interfaces. In particular, the slip phenomenon had been a debated subject for decades before the phenomenon was proven at a molecular level. Since the slip behavior is widely acknowledged, its fundamental relationships with other measurable physical properties have been studied intensively. Here, we present a first-principles-based multiscale simulation study on various solid–water interfacial systems to understand how the physical quantities influence the slip length. Based on the simulation results, we propose an extended quasi-universal relationship between the slip length and the work of adhesion by considering the surface packing density. Furthermore, we scrutinize the effects of the electron density tail from the solid wall on both the slip length and work of adhesion. We also investigate the relationship between the self-diffusivity of the fluid at the interface and the slip length. Our present study underlines the impact of atomic-level details of the solid–liquid interfaces, such as the surface packing structure and electrostatic interactions, on determining the hydrodynamic boundary conditions.