Highly oil-dispersed functionalized reduced graphene oxide nanosheets as lube oil friction modifier

Unique mechanical properties of graphene make it an attractive candidate for many tribological applications such as additives for lube oil. However, within a few days of its preparation, graphene suffers from agglomeration and it can be prevented by introducing large structure molecules on the surface of GO. Covalent functionalization of GO is possible because there are multiple oxygen-containing functionalities on GO sheets. The conversion of highly water-soluble GO to high oil-soluble GO was also possible by covalent functionalization method. In this study, oil-soluble GO sheets were fabricated via functionalization of GO with organic moiety using CuAAC via Click chemistry. This study demonstrates that chemical strategy to provide graphene with organic moiety is important to obtain highly oil-dispersed GO sheets. This study revealed that the rGO(f) shows a significant effect in reducing friction and wear by 16% and 30% respectively and proved to be easily dispersed in oil. (C) 2017 Elsevier B.V. All rights reserved.