Electrochemical Dissolution Of Copper Research Articles

Dinuclear chelates of acyclic and cyclic tridentate Schiff bases derived from sterically hindered o-aminophenols. A new type of reactivity of tridentate ligands under electrosynthesis conditions

The chemical and electrochemical synthesis of cobalt(II), nickel(II), and copper(II) complexes based on sterically hindered tridentate Schiff bases obtained by the coupling of 2-amino-4,6-di-tert-butylphenol with salicylaldehyde derivatives (H2L, H2L’) was performed. The resulting dinuclear complexes were characterized by elemental analysis, IR spectroscopy, and magnetochemical measurements in the 300–2 K temperature range. The structures of the dinuclear nickel(II) and copper(II) complexes with the composition Ni2L2·2AcOH·2MeOH and Cu2L2, respectively, were established by X-ray diffraction. The copper chelates are characterized by the presence of antiferromagnetic exchange interactions. The mononuclear copper(II) complexes (DMSO)bis[2-(5,7-di-tert-butyl-4-hydroxybenzoxazol-2-yl)phenolato]copper(II) and (DMF)2bis[2-(5,7-di-tert-butyl-4-hydroxybenzoxazol-2-yl)phenolato]copper(II) were isolated upon electrochemical dissolution of copper(0) and were structurally characterized.

Controlling Chaos with Artificial Neural Network: Numerical Studies and Experiments

Although there are a number of theoretically suggested chaos control methods using artificial neural networks (ANN), experimental tests are still lacking. In this paper, we report on experimental chaos control during the electrochemical dissolution of copper in phosphoric acid. The neural network implementation of simple proportional and recursive feedback algorithms is presented.

Electrochemical interfacial phenomena under microgravity: Part I. Anodic dissolution of copper in drop shaft

As part of a series of physical modeling studies on the electrochemical etching of a printed wiring board, copper foil was anodically dissolved in a small cavity. Coupling of the ionic mass transfer rate with the undercutting phenomena must be precisely understood in order to finely control high aspect ratio anisotropic etching. Interferometry has been applied to the study of the ionic mass transfer rate accompanying electrochemical reactions, and it may help in the visualization of the concentration profile of the metal ion within a narrow cavity. As an idealistic case, the electrochemical dissolution of copper in a purely diffusional field, especially the Cu2+ ion transfer rate itself, is now the focus of attention. The copper anode was galvanostatically dissolved in an aqueous solution (0.1M CuSO4-1M H2SO4) contained in a quasi-two-dimensional electrolytic cell for 8 seconds during free fall in a drop shaft. A disk type of anode, 1 mm in diameter and 100 µm in thickness, and a flat shaped ring cathode 20 mm in inner diameter were sandwiched by two sheets of slide glass. The electrolyte layer was 200 µm in effective thickness. The interference fringe pattern accompanying the copper dissolution was measured in situ with a common path-type microscopic laser interferometer. Terrestrial experiments were also conducted with a horizontally installed cell under the same electrolytic conditions. No natural convection would be expected in the present electrolytic cell design with such a shallow and horizontal electrolyte layer. The distance between the anode surface and the location at which the outer interference fringe appeared was measured by the duration time. It increased linearly with the square root of time under microgravity, but started to deviate from this linearity a few seconds after starting the electrolysis in the terrestrial experiment. A significant difference in the growing distance between the environments had not been a priori anticipated for such a quasi-two-dimensional cell. The local current density distribution along the smaller electrode surface may be influenced by induction of a kind of natural convection.