The Young-Laplace equation for a solid-liquid interface
Abstract
The application of the Young-Laplace equation to a solid-liquid interface is considered. Computer simulations show that the pressure inside a solid cluster of hard spheres is smaller than the external pressure of the liquid (both for small and large clusters). That would suggest a negative value for the interfacial free energy. We show that in a Gibbsian description of the thermodynamics of a curved solid-liquid interface in equilibrium, the choice of the thermodynamic (rather than mechanical) pressure is required, as suggested by Tolman for the liquid-gas scenario. With this definition, the interfacial free energy is positive, and the values obtained are in excellent agreement with previous results from nucleation studies. Although for a curved fluid-fluid interface there is no distinction between mechanical and thermal pressures (for a sufficiently large inner phase), in the solid-liquid they do not coincide, as hypothesized by Gibbs.
Cite
@article{arxiv.2401.12606,
title = {The Young-Laplace equation for a solid-liquid interface},
author = {P. Montero de Hijes and K. Shi and E. G. Noya and E. E. Santiso and K. E. Gubbins and E. Sanz and C. Vega},
journal= {arXiv preprint arXiv:2401.12606},
year = {2024}
}