Observation of slip flow in thermophoresis.
Two differing theories aim to describe fluidic thermophoresis, the movement of particles along a temperature gradient. While thermodynamic approaches rely on local equilibrium, hydrodynamic descriptions assume a quasi-slip-flow boundary condition at the particle's surface. Evidence for slip flow is presented for the case of thermal gradients exceeding (aS_(T)(-1) with particle radius a and Soret coefficient S_(T). Thermophoretic slip flow at spheres near a surface attracts or repels tracer particles perpendicular to the thermal gradient. Moreover, particles mutually attract and form colloidal crystals. Fluid dynamic slip explains the latter quantitatively.
Weinert
Franz M
FM
Systems Biophysics, Ludwig Maximilians Universität München, Amalienstrasse 54, Munich, Germany.
Braun
Dieter
D
D000465:Algorithms; D003460:Crystallization; D004247:DNA / Q000737:chemistry; D004563:Electrochemistry; D020342:Finite Element Analysis; D053758:Nanoparticles; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics
D011137:Polystyrenes; D004247:DNA