The effective interfacial tensions between pure liquids and rough solids: a coarse-grained simulation study

• Published in: Physical chemistry chemical physics : PCCP Vol. 25; no. 15; pp. 1325 - 1334
• Main Authors: Hernández Velázquez, J. D, Sánchez-Balderas, G, Gama Goicochea, A, Pérez, E
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 12.04.2023
• Subjects: Liquid-solid interfaces; Liquid-solid systems; Liquids; Mathematical analysis; Simulation; Solid phases; Solid surfaces; Surface roughness; Surface tension; Tensors
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d2cp04321a

The effective solid-liquid interfacial tension (SL-IFT) between pure liquids and rough solid surfaces is studied through coarse-grained simulations. Using the dissipative particle dynamics method, we design solid-liquid interfaces, confining a pure liquid between two explicit solid surfaces with different roughness degrees. The roughness of the solid phase is characterized by Wenzel's roughness factor and the effective SL-IFT is reported as a function of it also. Two solid-liquid systems, different from each other by their solid-liquid repulsion strength, are studied to measure the effects caused by the surface roughness on the calculation of . It is found that the roughness changes the structure of the liquid, which is observed in the first layer of liquid near the solid. These changes are responsible for the effective SL-IFT increase, as surface roughness increases. Although there is a predominance of surface roughness in the calculation of it is found that the effective SL-IFT is directly proportional to the magnitude of the solid-liquid repulsion strength. The insights provided by these simulations suggest that the increase of Wenzel's roughness factor increases the number of effective solid-liquid interactions between particles, yielding significant changes in the local values of the normal and tangential components of the pressure tensor. The increase of the effective solid-liquid interfacial tension between pure liquids and surfaces with random features is due to the variations of the local pressure due to the adsorbed liquid in the solid.