Fluid-Fluid Interfaces of Multi-Component Mixtures in Local Equilibrium

We derive in a new way that the intensive properties of a fluid-fluid Gibbs interface are independent of the location of the dividing surface. When the system is out of global equilibrium, this finding is not trivial: In a one-component fluid, it can be used to obtain the interface temperature from...

Full description

Bibliographic Details
Main Authors: Dick Bedeaux, Signe Kjelstrup
Format: Article
Language:English
Published: MDPI AG 2018-04-01
Series:Entropy
Subjects:
Online Access:http://www.mdpi.com/1099-4300/20/4/250
Description
Summary:We derive in a new way that the intensive properties of a fluid-fluid Gibbs interface are independent of the location of the dividing surface. When the system is out of global equilibrium, this finding is not trivial: In a one-component fluid, it can be used to obtain the interface temperature from the surface tension. In other words, the surface equation of state can serve as a thermometer for the liquid-vapor interface in a one-component fluid. In a multi-component fluid, one needs the surface tension and the relative adsorptions to obtain the interface temperature and chemical potentials. A consistent set of thermodynamic properties of multi-component surfaces are presented. They can be used to construct fluid-fluid boundary conditions during transport. These boundary conditions have a bearing on all thermodynamic modeling on transport related to phase transitions.
ISSN:1099-4300