A dynamical theory of nucleation for colloids and macromolecules

TL;DR

This paper develops a comprehensive dynamical theory of nucleation in colloids and macromolecules using fluctuating hydrodynamics, providing pathways, stochastic equations, and extending classical approaches with applications to protein transitions.

Contribution

It introduces a formalism for nucleation pathways and stochastic differential equations, extending classical nucleation theory within a fluctuating hydrodynamics framework.

Findings

Identifies a two-step nucleation mechanism in globular proteins.

Provides a formalism for nucleation pathways and stochastic evolution.

Extends classical nucleation theory with a dynamical approach.

Abstract

A general theory of nucleation for colloids and macromolecules in solution is formulated within the context of fluctuating hydrodynamics. A formalism for the determination of nucleation pathways is developed and stochastic differential equations for the evolution of order parameters are given. The conditions under which the elements of Classical Nucleation Theory are recovered are determined. The theory provides a justification and extension of more heuristic equilibrium approaches based solely on the free energy. It is illustrated by application to the low-concentration/high-concentration transition in globular proteins where a novel two-step mechanism is identified where the first step involves the formation of long-wavelength density fluctuations and the second step is the actual nucleation event occuring within the fluctuation.