Eur. Phys. J. E (2009) 28: 27-45
https://doi.org/10.1140/epje/i2008-10419-y

Regular Article

Modeling phase behavior for quantifying micro-pervaporation experiments

Laboratoire PCT, UMR “Gulliver” CNRS-ESPCI 7083, 10 rue Vauquelin, 75231, Paris cedex 05, France

^* e-mail: michael.schindler@espci.fr

Received: 5 September 2008
Accepted: 19 November 2008
Published online: 13 January 2009

Abstract

We present a theoretical model for the evolution of mixture concentrations in a micro-pervaporation device, similar to those recently presented experimentally. The described device makes use of the pervaporation of water through a thin PDMS membrane to build up a solute concentration profile inside a long microfluidic channel. We simplify the evolution of this profile in binary mixtures to a one-dimensional model which comprises two concentration-dependent coefficients. The model then provides a link between directly accessible experimental observations, such as the widths of dense phases or their growth velocity, and the underlying chemical potentials and phenomenological coefficients. It shall thus be useful for quantifying the thermodynamic and dynamic properties of dilute and dense binary mixtures.