Thermophoresis as a probe of particle-solvent interactions: The case of protein solutions

Thermophoresis, or thermal diffusion, consists in particle drift induced by thermal gradients. We discuss the physical mechanisms underlying thermophoresis in colloidal suspensions and macromolecular solutions, and present a general model suggesting thermophoretic measurements as a sensitive probe of particle-solvent interfacial properties. After reviewing recent results obtained by our group on thermal diffusion in charged colloidal systems, we discuss thermophoresis in protein solutions as a specific 'case study'.