Prof. B. Zaltzman (Ben Gurion University of the Negev, Israel)
Wednesday, May 6, 2020 - 15:15
Weierstraß-Institut
Mohrenstr. 39, 10117 Berlin, talk via Zoom -- please see seminar website 15 minutes before talk starts
Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Isaak Rubinstein and Boris Zaltzman. In this presentation we report that equilibrium electro-convective instability is possible in concentration polarization in the course of cathodic electrodeposition. The cathode is modelled as an ideally perm-selective interface with infinite lateral conductivity. The cation transfer across the cathode/solution interface is assumed to obey the Butler--Volmer kinetics with parameters typical of copper deposition. It is shown that deviation from the local reaction equilibrium due to the final deposition reaction rate renders possible the equilibrium electro-convective instability with a critical wavelength on the scale of diffusion layer width. This scaling may be recognized as a characteristic signature of equilibrium instability as opposed to the non-equilibrium one, related to the extended space charge. This latter instability, owning to its shortwave character, is characterized by origination of critical small vortices with a wavelength considerably shorter that the width of the diffusion layer. Interaction of these small scale vortices yields their fusion through which they evolve until reach a size comparable to the width of the diffusion layer.
submitted by eismann (andrea.eismann@wias-berlin.de, 030 20372320)