Comparing brightness of nanocrystalline nickel coating with traditional bright nickel coating and investigation of stereochemistry of brightener molecules

Abstract

ABSTRACT Nanocrystalline nickel coatings can be electrodeposited by using grain refiners like saccharin which consequently increase the gloss of the coating. Also, brighteners can produce bright coatings. The aim of this research was to compare the brightness of electroplated nanocrystalline nickel coating with traditional electroplated bright nickel coating. The coatings prepared from the bath containing saccharin and a bath with para-toluene sulphonamide had virtually the same gloss. Thus, instead of expensive brightening agents, saccharin can be used to achieve the same gloss in nickel plating. To investigate the stereochemistry of brightener molecules, the density functional theory (DFT) method was used at the computational level of B3LYP with the basis set 6-311G (d,p) ++ in a Gaussian software. The results of computational chemistry showed that the most probable state of adsorption of brightening additives is when the aromatic ring or a double bond or a triple bond of the brightener molecule approaches the cathode surface during the adsorption process.