Impact of the Interfacial\nKapitza Resistance on Colloidal\nThermophoresis

Thermal gradients impart thermophoretic forces on colloidal\nparticles,\npushing colloids toward cold or hot regions, a phenomenon called thermophoresis.\nCurrent theoretical approaches relate the Soret coefficient to local\nchanges in the interfacial tension around the colloid, which lead\nto fluid flow around the colloid surface. The Kapitza resistance,\na key variable in the description of interfacial heat transport, is\nan experimentally accessible property that modifies interfacial thermal\nfields. Here, we introduce a theoretical approach that describes colloid\nthermophoretic forces by incorporating explicitly Kapitza resistance\neffects. Our formulation can be used to monitor the dependence of\nthermophoresis on interfacial thermal resistance. We show that the\nresistance modifies the thermal field around the colloids and identify\nexperimental conditions where the Kapitza resistance influences the\nthermophoretic forces. We validate our theoretical approach by implementing\na nonequilibrium molecular dynamics model of a colloid suspended in\na solvent.