The Hydrophobic Aggregation of Two Colloids: A Thermodynamic Model

TL;DR

This paper presents a thermodynamic model explaining colloidal aggregation driven by hydrophobic effects, emphasizing entropy production and solvent molecule desorption as key factors in destabilization.

Contribution

It introduces a thermodynamic framework based on Prigogine's out-of-equilibrium thermodynamics to explain colloidal aggregation mechanisms.

Findings

Aggregation involves solvent desorption from colloids.

Entropy production drives irreversible aggregation.

Destabilization linked to chemical potential minimization.

Abstract

Colloidal aggregation could be implemented in various fields ranging from purely colloidal thermodynamics to protein interactions, their stability, and maybe folding. Indeed, colloidal aggregation is closely linked to the so-called hydrophobic effect for which a thermodynamic explanation is proposed. This explanation is performed using Prigogine's out-of-equilibrium thermodynamics which is based on entropy production. It is shown that a likely destabilizing event could induce a spontaneous and irreversible aggregation of two identical or different colloids as it causes the desorption of solvent molecules from colloidal surfaces. This desorption is an entropy production factor through the chemical potentials minimization of, among others, initially adsorbed molecules. This may be viewed as an increase of the so-called "solvent entropy" or "translational entropy".