This title appears in the Scientific Report : 2015 

Effect of Fluid-Colloid Interactions on the Mobility of a Thermophoretic Microswimmer in Non-Ideal Fluids
Fedosov, Dmitry (Corresponding author)
Sengupta, Ankush / Gompper, Gerhard
Theorie der Weichen Materie und Biophysik ; IAS-2
Theorie der Weichen Materie und Biophysik ; ICS-2
Soft matter, 11 (2015) 33, S. 6703-6715
London Royal Soc. of Chemistry 2015
26223678
10.1039/C5SM01364J
Journal Article
Functional Macromolecules and Complexes
OpenAccess
OpenAccess
Please use the identifier: http://hdl.handle.net/2128/9652 in citations.
Please use the identifier: http://dx.doi.org/10.1039/C5SM01364J in citations.
Janus colloids propelled by light, e.g., thermophoretic particles, offer promising prospects as artificial microswimmers. However, their swimming behavior and its dependence on fluid properties and fluid–colloid interactions remain poorly understood. Here, we investigate the behavior of a thermophoretic Janus colloid in its own temperature gradient using numerical simulations. The dissipative particle dynamics method with energy conservation is used to investigate the behavior in non-ideal and ideal-gas like fluids for different fluid–colloid interactions, boundary conditions, and temperature-controlling strategies. The fluid–colloid interactions appear to have a strong effect on the colloid behavior, since they directly affect heat exchange between the colloid surface and the fluid. The simulation results show that a reduction of the heat exchange at the fluid–colloid interface leads to an enhancement of colloid's thermophoretic mobility. The colloid behavior is found to be different in non-ideal and ideal fluids, suggesting that fluid compressibility plays a significant role. The flow field around the colloid surface is found to be dominated by a source-dipole, in agreement with the recent theoretical and simulation predictions. Finally, different temperature-control strategies do not appear to have a strong effect on the colloid's swimming velocity.