Ion transport and deposit growth in spatially coupled bipolar electrochemistry

JC BRADLEY; S DENGRA,; GA GONZALEZ,; G MARSHALL,; F. V. MOLINA

JOURNAL OF ELECTROANALYTICAL CHEMISTRY

Elsevier

Lugar: Amsterdam; Año: 1999 vol. 478 p. 128 - 139

0022-0728

In spatially coupled bipolar electrochemistry, electrodissolution andelectrodeposition processes in an applied electric field are exploited tocreate directional growth of copper deposits between two copper discs notphysically linked to an external voltage source. Here we study the electricfield in the whole cell through theoretical modelling, and ion transport inthe interdisc region using optical and particle image velocimetrytechniques. Their combined effect on incubation time and deposit morphologyis assesed. Both the electric field and ion transport in the interdiscregion are crucial factors in the characteristics of the interconnection.The model simulations reveal that the electric field is almost an order ofmagnitude larger in the region between discs as compared with the mean fieldvalue. Measurements and simulations show that the incubation time scaleslinearly with the inverse of the electric field, an indication that in thisperiod migration is the dominant transport mode. Experiments reveal thatafter branching develops, convection plays a relevant role as well, thecontact growing linearly in time, with a change of the time/length slope athalf the interdisc gap.