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Tribological Behavior of Nano-Onions in Krytox 143AB EvaluatedNanoparticles have been developed over the past 10 years and have found several applications. This work presents the use of carbon nano-onions as a potential oil additive for aerospace applications. Researchers at the NASA Glenn Research Center tested lubricant lifetimes in ambient air and ultrahigh vacuum and characterized the breakdown products of the friction and wear. These carbon nanoparticles can provide adequate lubrication very similar to that of graphitic material when run in air. Soot represents one of the very first nanostructured materials, although it has rarely been considered as such. Changes in the carbon nanostructure, resulting in increased graphitic layer plane length, correlate with reactivity loss. Upon heating spherically shaped nanometer-sized carbon black in the absence of oxidant, graphene sheets form, and the initial soot particle templates the growth of a graphitic particle into what is best described as a sphere with many flat sides having a hollow interior. Because there are no edge sites, these polygonal graphitic particles, or nano-onions, are relatively resistant to oxidation. Graphite is used as a solid lubricant because of its stability at moderately high temperatures. However, the temperature at which graphite oxidizes rapidly is strongly influenced by surface area. With the size of particles typically employed in lubrication, a great amount of thermal stability is lost because of size reduction either during preparation or during lubrication of contacting parts. Therefore, we have undertaken a study of the lubricating ability of graphitic nano-onions (ref. 1).
Document ID
Acquisition Source
Glenn Research Center
Document Type
Street, Kenneth W.
(NASA Glenn Research Center Cleveland, OH, United States)
VanderWal, Randy L.
(National Center for Space Exploration Research on Fluids and Combustion Cleveland, OH, United States)
Marchetti, Mario
Tomasek, Aaron J.
Date Acquired
September 7, 2013
Publication Date
June 1, 2005
Publication Information
Publication: Research and Technology 2004
Subject Category
Mechanical Engineering
Distribution Limits
Work of the US Gov. Public Use Permitted.
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