Development of Low-Friction Technology for Treating Nitrogen-Containing Diamond-Like Carbon Coatings in Ambient Air Using Dielectric Barrier Discharge

In this study, we develop a new surface treatment technology for diamond-like carbon (DLC) coatings using dielectric barrier discharge (DBD) in ambient air. After DBD irradiation, the friction coefficient was reduced from 0.26 to about 0.01. It was also found that the surface exhibited super hydrophilicity and high surface energy after DBD irradiation. In particular, nitrogen-containing DLC produces an acidic liquid film on its surface after DBD irradiation. Surface analysis indicated that the introduction of oxygen-containing groups on the surface after DBD irradiation might be the reason for the superhydrophilicity. The reason for the low friction was the interaction between the graphitized material and the highly acidic liquid.