Electroless deposition of Ni–P–nano-ZrO2 composite coatings in the presence of various types of surfactants

Ni–P–nano-ZrO2 coatings were produced using the electroless deposition technique. To prevent agglomeration of zirconia nanoparticles in the plating bath, various surfactant additives (anionic, cationic, and nonionic) were used. The most stable bath was obtained with the addition of dodecyltrimethylammonium bromide (DTAB). The impact of this surfactant on the deposition rate, coating composition, and topography, as well as ζ potential of particles, was examined. Surface morphology and composition of the Ni–P–nano-ZrO2 composite coatings was analyzed by various techniques including scanning electron microscopy (SEM) equipped with in situ energy-dispersive X-ray (EDX) spectroscopy. Coatings with a clearly greater amount of zirconia (21.88–22.10 wt.%) were obtained from baths containing DTAB in concentrations equal to or above its critical micelle concentration (cmc). For these surfactant concentrations, the reduction of Ni and P content was observed.

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► Ni–P–nano-ZrO2 coatings have been obtained from baths stabilized by surfactants.
► Addition of surfactants affects the plating bath stability.
► In the presence of DTAB Ni–P coatings with high content of ZrO2 can be obtained.