Anisotropic Wetting of Hydrophobic and Hydrophilic Surfaces–Modelling by Lattice Boltzmann Method

Anisotropic wetting on unidirectionally textured surfaces was investigated by Lattice Boltzmann Method. Previously published experimental data were used to validate the numerical model. New analysis were carried out by changing static contact angle of grooved surfaces from hydrophilic to hydrophobic (θs = 50 – 150°). Presented results suggests that anisotropic wetting on unidirectionally textured surfaces is governed by spreading along the grooves by capillary action and mainly is dominant in Wenzel state on hydrophilic surfaces. Transition to Cassie-Baxter state on hydrophobic surfaces (θs > 90°) significantly reduces the effect of anisotropic wetting. Structured texture and/or chemical heterogeneity can be potentially used to manipulate droplets in case of hydrophobic surfaces.