Cathodic electrodeposition of superhydrophobic coatings based on Nickel carboxylates: effect of the carboxylic acid chain on surface morphology and composition

Nickel-based hydrophobic surfaces were cathodically electrodeposited from ethanolic solutions of nickel nitrate and carboxylic acids. In order to investigate the effect of the type of carboxylic acid, various acids including Myristic acid CH۳(CH۲)۱۲COOH, Palmitic acid CH₃(CH₂)₁₄COOH, Oleic acid CH۳(CH۲)۷CH=CH(CH۲)۷COOH and Stearic acid CH₃(CH₂)₁₆COOH were used as the source of the carboxylate anion. Potentiostatic electrodeposition gave hydrophobic surfaces from all of the above mentioned carboxylic acids. Surface morphology, elemental composition, structure and hydrophobicity of the nickel-based coatings were investigated by Scanning Electron Micriscopy (SEM), Energy Dispersive X-Ray Spectrometry (EDS), Fourier Transform Infra-Red (FTIR) Spectrometry and water contact angle (WCA) measurements, respectively. The results showed that the type of acid has a significant effect on the morphology, composition, elemental composition and hydrophobicity of the deposited layer. Generally, the acids with longer chains resulted in lower nickel content and more hydrophobicity.

Keywords:

Electrodeposition , Hydrophobic Surfaces , Nickel carboxylates