The role of diffusion, migration and convection in thin-layer spatially coupled bipolar electrochemistry

J. C. BRADLEY, S. DENGRA, G. GONZÁLEZ, G. MARSHALL, F. MOLINA

Santa Fe, Argentina

Congreso; XI Congreso Argentino de Fisicoquímica y Química Inorgánica y I Congreso de Fisicoquímica del Mercosur; 1999

Asociación Argentina de Investigación Fisicoquímica

Electrodissolution and electrodeposition process in an applied electric field can be exploited to create directional growth of copper deposits between two copper particles not physically linked to an external voltage source. Because the material electodeposited on one of the particles originates from the dissolution of the other particle and each particle serves as both anode and cathode, this is termed spatially coupled bipolar electrochemistry (SCBE). Ion transport is mainly driven by diffusion, migration and convection. Convection was shown to be relevant in monopolar thin-layer electrodeposition. Convection is driven mainly by coulombic forces and by buoyant forces. Here we study experimentally the different transport modes involved in SCBE, particularly convection, and their effect on ion transport, induction time and deposit morphology. These are determinant in the characteristics of the interconnection. Preliminary conclusions show that convection has a relevant role as well in SCBE and that deposit thickness and induction time inversely proportional to the electric field. A theoretical interpretation is advanced.