Antibacterial characteristics of electroless plating Ni–P–TiO2 coatings

Electroless Ni–P coatings have been widely used in the chemical, mechanical and electronic industries due to their excellent corrosion and wear resistance. Many studies reported that the incorporation of nano-sized particles TiO2 into Ni–P matrix greatly improved their anti-corrosion and anti-wear resistance. However no studies have been reported on their anti-bacterial property. In this paper, the Ni–P–TiO2 nano-composite coatings were prepared on stainless steel 316L using electroless plating technique. The experimental results showed that the Ni–P–TiO2 coatings reduced the adhesion of three bacterial strains (Pseudomonas fluorescens, Cobetia and Vibrio) by up to 75% and 70% respectively, as compared with stainless steel and Ni–P coatings. The electron donor surface energy of the Ni–P–TiO2 coatings increased significantly with increasing TiO2 content after UV irradiation. The number of adhered bacteria decreased with increasing electron donor surface energy of the coatings.