Effect of temperature and capillary number on wettability and contact angle hysteresis of various materials. Modeling taking into account porosity

Abstract

The effect of surface temperature and laser texturing on the wettability and contact angle hysteresis of Cu, Cu/G, AlMg3, Cu-SiC was considered. Modeling using molecular dynamics qualitatively confirms the experimental results: 1) an increase in the contact angle hysteresis on a textured surface; 2) influence of the surface wettability on contact angle hysteresis; 3) influence of the contact line velocity on contact angle hysteresis. Heating the sample of different composite materials can lead to either an increase in the contact angle or a decrease. It was shown that after laser texturing, a system of nano-micro pores was formed in the surface layer of the material, which leads to an abnormally high contact angle hysteresis on the Cu-SiC composite. A new model is proposed that explains the different qualitative behavior of the contact angle hysteresis in different studies with increasing capillary number (Ca), as well as with increasing sample temperature.