A comparative study on 2-Aminoethanethiol and l-Cysteine as new additives for electroforming nickel mesh

摘要

Electroforming of nickel mesh was performed in bath with different concentration of 2-Aminoethanethiol andl-Cysteine to achieve a higher aspect ratio. Although 2-Aminoethanethiol andl-Cysteine have a similar part in their molecules, the optical observation on the cross section of mesh indicated that 2-Aminoethanethiol was an effective additive in improving the aspect ratio of nickel printing mesh whereasl-Cysteine was not. Electrochemical behaviors of 2-Aminoethanethiol andl-Cysteine in the electroforming bath were further evaluated by linear sweep voltammetry (LSV) and galvanostatic measurements using rotating disk electrode (RDE). Both 2-Aminoethanethiol andl-Cysteine could effectively reduce the cathodic polarization and promote deposition of nickel ions. The depolarization effect of 2-Aminoethanethiol which associated with convection is stronger in the high diffusion region than that in the low diffusion region in the present potential region. However, the depolarization effect ofl-Cysteine which also associated with the convection is stronger in the low diffusion region than in the high diffusion region unless the potential is negative enough. The different depolarization behaviors under different convection conditions made significant influence on the deposition of nickel ions on the board surface and the internal surface, which finally leads to the high aspect ratio.