The coexistence region in the Van der Waals fluid and the liquid-liquid phase transitions

Dinh Quoc Huy Pham; Mateusz Chwastyk; Marek Cieplak

doi:10.3389/fchem.2022.1106599

The coexistence region in the Van der Waals fluid and the liquid-liquid phase transitions

Front Chem. 2023 Jan 25:10:1106599. doi: 10.3389/fchem.2022.1106599. eCollection 2022.

Authors

Dinh Quoc Huy Pham¹, Mateusz Chwastyk¹, Marek Cieplak¹

Affiliation

¹ Institute of Physics, Polish Academy of Sciences, Warsaw, Poland.

Abstract

Cellular membraneless organelles are thought to be droplets formed within the two-phase region corresponding to proteinaceous systems endowed with the liquid-liquid transition. However, their metastability requires an additional constraint-they arise in a certain region of density and temperature between the spinodal and binodal lines. Here, we consider the well-studied van der Waals fluid as a test model to work out criteria to determine the location of the spinodal line for situations in which the equation of state is not known. Our molecular dynamics studies indicate that this task can be accomplished by considering the specific heat, the surface tension and characteristics of the molecular clusters, such as the number of component chains and radius of gyration.

Keywords: Van der Waals fluid; intrinsically disordered proteins (IDPs); liquid-liquid phase transitions; molecular dynamics simulations (MD); phase diagam.

Grants and funding

This research has received support from the National Science Centre (NCN), Poland, under grant No. 2018/31/B/NZ1/00047 and the European H2020 FETOPEN-RIA-2019-01 grant PathoGelTrap No. 899616. The computer resources were supported by the PL-GRID infrastructure. This project is also a part of the European COST Action EUTOPIA.