Thermophoresis as persistent random walk

TL;DR

This paper models thermophoresis as a persistent random walk with velocity fluctuations, linking microscopic particle dynamics to macroscopic drift in temperature gradients, and reproduces key thermophoresis results.

Contribution

It introduces a simple one-dimensional random walk model with position-dependent velocity to explain thermophoresis phenomena.

Findings

Reproduces basic thermophoresis results

Models particle drift along temperature gradients

Connects microscopic dynamics to macroscopic behavior

Abstract

In a simple model of a continuous random walk a particle moves in one dimension with the velocity fluctuating between V and -V. If V is associated with the thermal velocity of a Brownian particle and allowed to be position dependent, the model accounts readily for the particle's drift along the temperature gradient and recovers basic results of the conventional thermophoresis theory.