| 研究実績の概要 |
1) We have developed multilayer polyethylenimine / graphene oxide thin films by a highly scalable layer by layer (LbL) deposition technique can be used as solid lubricants. The tribological properties are investigated in air, under vacuum, in hydrogen, and in nitrogen gas environments.
2) First time ever, ultra-low friction coefficients (Superlubricity regime, µ < 0.04) were observed in hydrogen and nitrogen for graphene oxide based coatings. The Tribological results show that the friction behavior in dry environment (vacuum, H2 and N2) is very different from humid environment (ambient air)
3) Microstructural analysis of the wear debris revealed that this is likely due to the formation of carbon nanoparticles in dry conditions (N2, vacuum), but not in the presence of moisture (air, H2). Such nanoparticles reduce the COF by introducing asperities and thereby decreasing the contact area.
4) The mechanism behind this microstructural difference was elucidated via density functional theory (DFT) simulations, which showed that strong hydrogen bonding occurs between graphene oxide sheets under pressure and in the presence of water, preventing the formation of nanostructures.
5) This work was accepted for oral presentation in STLE 2016 and Manuscript on this work will be submitted soon.
(Note : Confidential)
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