The effect of multi-walled carbon nanotube pretreatments on the electrodeposition of Ni–MWCNTs coatings

Two different chemical treatments were performed on multi-walled carbon nanotubes (MWCNTs), namely functionalization, and shortening-functionalization processes. Then, nickel–MWCNTs coatings were co-electrodeposited. The results showed that the chemically shortened nanotubes were behaved as inert particles, and embedded into the nickel matrix, whilst the long functionalized nanotubes showed metallic behavior and during electrodeposition, they were incorporated into the nickel matrix. In similar plating condition, the amount of co-deposited shortened nanotubes was more than elongated ones. Furthermore, it was revealed that the pretreatment of nanotubes significantly affected the microstructure, surface morphology, hardness and corrosion resistance of deposited coatings.