Estimating contact angle of pure and mixed liquids on smooth solid surfaces using dispersive-to-attractive surface energy ratio from PCP-SAFT model

This study introduces a novel methodology using the PCP-SAFT model and Young equation to estimate contact angles of pure and mixed liquids on solid surfaces. By considering the dispersion and non-dispersion contributions to the Helmholtz energy, our approach estimates the ratio of dispersion to total surface energy, that is crucial to predict contact angles. Comparing our results with literature data demonstrates high accuracy; the average absolute relative deviation (AARD) of 6.65% is achieved for estimating the ratio of dispersion surface tension to total surface tension of 13 liquids and 9.27% for estimating contact angle for 70 systems at room condition. Moreover, our model effectively captures the temperature and composition variations for binary mixtures on various surfaces, showing its applicability in understanding the wetting behavior. The PCP-SAFT model offers a promising tool for estimating the ratio of dispersion surface tension to total surface tension, required to estimate contact angle as an important measure of surface wetting.