2017/03/31 by Aboubakry Ly, Arghya Majee, Alois Würger · 25 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Colloid #Electrolyte #Janus #Micro and Nano Robotics #Microsecond #Nanoscopic scale #Nanostructure #Polarization (electrochemistry) #Surface charge #Thermoelectric effect #cond-mat.soft #stochastic dynamics and bifurcation
paper · pdf · doi:10.1088/1367-2630/aaa266
published in New Journal of Physics 20(2), 025001 (IOP Publishing) · 33 pages, 5 figures
openalex publication_date 2017/12/18 · openalex created_date 2018/01/05 · arxiv created 2018/02/26 · arxiv updated 2018/02/27 · openalex updated_date 2026/08/05
We theoretically study the electrolyte Seebeck effect in the vicinity of a heated metal nanostructure, such as the cap of an active Janus colloid in an electrolyte, or gold-coated interfaces in optofluidic devices.The thermocharge accumulated at the surface varies with the local temperature, thus modulating the diffuse part of the electric double layer.On a conducting surface with non-uniform temperature, the isopotential condition imposes a significant polarization charge within the metal.Surprisingly, this does not affect the slip velocity, which takes the same value on insulating and conducting surfaces.Our results for specific-ion effects agree qualitatively with recent observations for Janus colloids in different electrolyte solutions.Comparing the thermal, hydrodynamic, and ion diffusion time scales, we expect a rich transient behavior at the onset of thermally powered swimming, extending to microseconds after switching on the heating.