Wetting behavior of sessile droplet affected by chemical heterogeneity size: A theoretical and simulative analysis with consideration of contact line width

YS Wen and YS Liu, CHEMICAL ENGINEERING SCIENCE, 258, 117776 (2022).

DOI: 10.1016/j.ces.2022.117776

The effect of surface heterogeneity of solid substrate on the wetting behavior of sessile droplets is systematically investigated. A theory is proposed to predict the contact angle by considering the droplet to be a spherical cap and the contact line to have a width. Comprehensive molecular dynamics (MD) simulations are implemented to validate this theory, which shows good agreement. Based on this theory, the relationship between the wetting behavior of sessile droplets and the heterogeneity pattern of chemically heterogeneous surfaces is established, which manifests that the contact angle can be precisely controlled. Further, the influence of the heterogeneity size on wetting is quantified, which indicates that the contact angle behavior is quite distinct with the contact line width as the critical value of the heterogeneity size. The reason is analyzed theoretically through the location of the contact line with a width, giving an intuitive comprehension of the underlying mechanism. CO 2022 Published by Elsevier Ltd.

Return to Publications page