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.