Phase-field modeling of solute precipitation and dissolution

TL;DR

This paper introduces a phase-field model for simulating solute precipitation and dissolution at liquid-solid interfaces, demonstrating convergence to sharp-interface limits and validating the approach with analytical solutions.

Contribution

It adapts and validates phase-field modeling techniques specifically for precipitation and dissolution processes, highlighting differences from solidification models.

Findings

The model converges to the sharp-interface limit.

Validation against analytical solutions confirms accuracy.

The approach effectively captures discontinuous concentration fields.

Abstract

A phase-field approach to the dynamics of liquid-solid interfaces that evolve due to precipitation and/or dissolution is presented. For the purpose of illustration and comparison with other methods, phase field simulations were carried out assuming first order reaction (dissolution/precipitation) kinetics. In contrast to solidification processes controlled by a temperature field that is continuous across the solid/liquid interface (with a discontinuous temperature gradient) precipitation/dissolution is controlled by a solute concentration field that is discontinuous at the solid/liquid interface. The sharp-interface asymptotic analysis of the phase-field equations for solidification [Karma and Rappel, Phys. Rev. E57 (1998) 4342] has been modified for precipitation/dissolution processes to demonstrate that the phase-field equations converge to the proper sharp-interface limit. The mathematical model has been validated for a one-dimensional precipitation/dissolution problem by comparison with the analytical solution.