IWNET12
IWNET12
Local equilibrium for interfaces and gauge transformations veried by
simulations
Marco Schweizer1, Thierry Savin1
1 ETH Zurich, Switzerland
Abstract
The classical approach to equilibrium interfacial thermodynamics in phase coexistence describes the interface as
a separate two dimensional thermodynamic system characterized by excess densities. Gibbs' original formulation
relies on the uniformity of intensive variables throughout the system. Therefore, it cannot be directly applied to
nonequilibrium situations such as evaporation/condensation processes or heterogeneous catalysis, where jumps
in temperature and chemical potential across the interface can occur.
We present a conceptually clear formulation of local equilibrium for interfaces [1]. In particular, we gain new
insights by formulating, in terms of gauge transformations, the ambiguity in locating the interface. This notably
allows us to generalize the Clapeyron relationships to nonequilibrium situations. We support our theoretical
predictions by performing stringent tests with extensive nonequilibrium molecular dynamics simulations.
References
[1] T. Savin, K. S. Glavatskiy, S. Kjelstrup, H. C. Öttinger and D. Bedeaux, Europhys. Lett., 97 (2012), 40002.
E-mail: marco.schweizer@mat.ethz.ch

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