Analysis of a viscoelastic phase separation model

J Phys Condens Matter. 2021 May 11;33(23). doi: 10.1088/1361-648X/abeb13.


A new model for viscoelastic phase separation is proposed, based on a systematically derived conservative two-fluid model. Dissipative effects are included by phenomenological viscoelastic terms. By construction, the model is consistent with the second law of thermodynamics. We study well-posedness of the model in two space dimensions, i.e., existence of weak solutions, a weak-strong uniqueness principle, and stability with respect to perturbations, which are proven by means of relative energy estimates. Our numerical simulations based on the new viscoelastic phase separation model are in good agreement with physical experiments. Furthermore, a good qualitative agreement with mesoscopic simulations is observed.

Keywords: dynamic structure factor; relative energy; viscoelastic phase separation; weak-strong uniqueness.