Effect of Diamond Nanoparticles in Electroless Ni-P-ND Coatings on Bacterial Anti-adhesive Behavior

The electroless Ni-P-ND composite coatings have been widely researched because of their extreme hardness, excellent resistance to corrosion and wear, etc. However few studies have been reported on their bacterial anti-adhesive property. In this paper, a systematic study of the bacterial anti-adhesive activity of electroless Ni-P-ND composite coatings on stainless steel 316L by electroless plating technique was performed. The data show that electroless Ni-P-ND composite coatings have much better bacterial anti-adhesive activity than stainless steel 316L. The experimental results have revealed that the Ni-P-ND composite coatings reduced the adhesion of Staphylococcus aureus cells by up to 75% in comparison to stainless steel 316L. The surface free energy and its components of the coatings, derived from contact angle measurements, were also studied in this paper. It was found that the electron donor components of surface free energy of the Ni-P-ND coatings increased with increasing the concentration of diamond nanoparticles suspension. The number of adhered bacteria decreased with increasing electron donor components of surface energy of the coatings. There was a strong correlation between the number of adhered bacteria and the electron donor components of surface free energy.