Acid Treatment of Diamond-Like Carbon Surfaces for Enhanced Adsorption of Friction Modifiers and Friction Performance
- 187 Downloads
Diamond-like carbon (DLC) is a class of amorphous carbon materials used as wear-resistant coatings in tribo-components. The chemical inertness of DLC surfaces, while important in many applications, makes them incompatible with additives in commercial lubricants. Specifically, DLC surfaces do not permit strong adsorption of friction modifier molecules. This study aims at improving the adsorption of these friction modifier molecules on DLC surfaces through an acid treatment. Water contact angle measurements show that such a treatment results in improved hydrophilicity of the DLC. XPS analysis demonstrates 50% increase in the uptake of ArmeenT, an organic friction modifier, on DLC after the acid treatment. This increased ArmeenT adsorption is accompanied by marked decrease in friction in micro-scale friction experiments.
KeywordsDLC Surface treatment Surface adsorption Friction modifiers
The authors gratefully acknowledge US Department of Energy for the research support under Contract DE-EE0006449 and US National Science Foundation for research support under Grant CMMI-1662606. We sincerely thank AkzoNobel for the generous supply of friction modifier used in this research. This work also made use of the EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the MRSEC program (NSF DMR-1720139) at the Materials Research Center, the International Institute for Nanotechnology (IIN), the Keck Foundation, and the State of Illinois (through the IIN).
- 12.Donnet, C.: Recent progress on the tribology of doped diamond-like and carbon allow coatings: a review. Surf. Coat. Technol. 180–186, 100–101 (1998)Google Scholar
- 13.Donnet, C., Erdemir, A.: Tribology of Diamond-Like Carbon Films: Fundamentals and Applications. Springer Science & Business Media, New York (2007)Google Scholar
- 14.Konicek, A.R., Grierson, D.S., Sumant, A.V., Friedmann, T.A., Sullivan, J.P., Gilbert, P.U.P.A., Sawyer, W.G., Carpick, R.W.: Influence of surface passivation on the friction and wear behavior of ultrananocrystalline diamond and tetrahedral amorphous carbon thin films. Phys. Rev. B 85(15), 155448 (2012)CrossRefGoogle Scholar