Solubility and Mixing in Fluids

TL;DR

This paper explores the physics of solubility and mixing in fluids, covering thermodynamics, statistical mechanics, and kinetics, with applications to polymers, surfactants, and colloids, highlighting diverse phenomena and their technological relevance.

Contribution

It provides a comprehensive analysis of mixing phenomena in fluids, integrating thermodynamics, statistical mechanics, and kinetics, with specific examples like polymers and surfactants.

Findings

Analysis of demixing and mixing mechanisms

Insights into polymer and surfactant behavior

Discussion of spinodal decomposition phenomena

Abstract

Traditionally, solubility and mixing belong to the realm of chemistry and material sciences and many standard textbooks on physical chemistry treat this problem, usually within the scope of thermodynamics. Here apart from thermodynamics we shall discuss other issues such as: the statistical mechanics theories of mixtures, relation between intermolecular interactions and demixing, coupling between ordering and demixing, and kinetics of demixing which includes spinodal decomposition in binary liquid mixtures. The following special examples will be discussed: polymer blends,diblock copolymers, liquid crystals, and ternary mixtures including surfactants (amphiphiles). Within the scope of physics of solubility and mixing one can study such diverse phenomena as: mixing of two simple liquids, collapse of the polymer chain in the solvent, flocculation of colloidal particle upon the addition of the polymer chains, mixing of two polymer components in a liquid state, ordering of copolymers and ternary mixtures of oil, water and surfactant or formation of micelles in aqueous solutions. In reality, very rarely we have completely pure substances, thus the properties of mixtures and the phenomenon of mixing and demixing are of prime importance for science and technology.