2006/09/21 by Stefan Duhr, Duhr, Stefan, Dieter Braun +1
Engineering · Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #Field-Flow Fractionation Techniques #Gas Dynamics and Kinetic Theory #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Statistical Mechanics (cond-mat.stat-mech) #cond-mat.mes-hall #cond-mat.stat-mech
paper · pdf · doi:10.48550/arxiv.cond-mat/0609554
9 pages, 4 Figures
arxiv created 2006/09/21 · openalex publication_date 2006/09/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Thermophoresis (thermodiffusion, Soret effect) moves molecules along thermal gradients. We measure its phenomenological linear drift relation by single particle tracking in convection-free settings. For moderate thermal gradients, drift velocity depends linearly on the gradient. However, for strong thermal gradients, we find a nonlinear dependence of the drift on the applied gradient for large Soret coefficient and particle radius. Interestingly, the onset of the nonlinearity coincides with a local disequilibrium of the particle. Nonlinear thermophoresis resolves several fundamental contradictions between thermophoretic experiments and theory.