Pattern formation in three-state systems: Towards understanding morphology formation in the presence of evaporation

TL;DR

This paper investigates how domain morphologies form in three-state systems, such as thin films with two solutes and a solvent, using computational models to understand effects of solvent content and evaporation.

Contribution

It introduces a combined lattice and continuum modeling approach to study morphology formation in ternary systems with solvent evaporation effects.

Findings

Morphology depends on solvent content and evaporation dynamics.

Lattice and continuum models produce consistent morphological patterns.

Evaporation significantly alters domain structures.

Abstract

Inspired by experimental evidence collected when processing thin films from ternary solutions made of two solutes, typically polymers, and one solvent, we computationally study the morphology formation of domains obtained in three-state systems using both a lattice model and a continuum counterpart. The lattice-based approach relies on the Blume-Capel nearest neighbor model with bulk conservative Kawasaki dynamics, whereas as continuum system we consider a coupled system of evolution equations that is derived as hydrodynamic limit when replacing the nearest neighbor interaction in the lattice case by a suitable Kac potential. We explore how the obtained morphology depends on the solvent content in the mixture. In particular, we study how these scenarios change when the solvent is allowed to evaporate.