Fluid Mechanical and Electrical Fluctuation Forces in Colloids

TL;DR

This paper compares fluid mechanical and electrical fluctuation forces in colloids, highlighting the dominance of electric fluctuation-induced van der Waals forces when quantum effects are considered, affecting colloid stability.

Contribution

It provides a detailed analysis of fluctuation forces in colloids, emphasizing the quantum effects on electric fluctuation forces compared to fluid mechanical forces.

Findings

Electric fluctuation forces dominate at the quantum level.

Fluid velocity and electric field forces are comparable classically.

Quantum effects enhance electric fluctuation forces.

Abstract

Fluctuations in fluid velocity and fluctuations in electric fields may both give rise to forces acting on small particles in colloidal suspensions. Such forces in part determine the thermodynamic stability of the colloid. At the classical statistical thermodynamic level, the fluid velocity and electric field contributions to the forces are comparable in magnitude. When quantum fluctuation effects are taken into account, the electric fluctuation induced van der Waals forces dominate those induced by purely fluid mechanical motions. The physical principles are applied in detail for the case of colloidal particle attraction to the walls of the suspension container and more briefly for the case of forces between colloidal particles.