Understanding the Temperature Dependence of Solid-Liquid Interfacial Properties

Knowledge of the temperature dependence of solid-liquid interfacial properties is necessary to design interfacial systems with a desired thermal response. In our recent work, we have studied how various wetting properties depend on temperature and the strength of the substrate-fluid interaction.¹ We are now interested in understanding the observed temperature dependence in terms of the nature of the fluid and solid substrate. We are particularly interested in conditions for which solid-fluid interfacial properties show negligible dependence on temperature.  In this presentation, we show how applying Gibbs formalism to express the interfacial tensions in terms of their energetic and entropic components provides a clearer picture on the above mentioned phenomena. These components help us in quantitatively relating the observed temperature dependence of interfacial properties to solid-fluid or fluid-fluid interactions and the arrangement of fluid molecules near the solid. We then explain how these energetic and entropic components are calculated from Monte Carlo simulations using free energy based approach developed in our group. Results are the provided, wherein this strategy is used to explain the temperature dependence of wetting properties of simple models of ionic liquids on solid substrates.

(1)          Rane, K. S.; Kumar, V.; Errington, J. R. Journal of Chemical Physics 2011, 135, 234102.