Role of oxygen functional groups in reduced graphene oxide for lubrication

Functionalized and fully characterized graphene-based lubricant additives are potential 2D materials for energy-efficient tribological applications in machine elements, especially at macroscopic contacts. Two different reduced graphene oxide (rGO) derivatives, terminated by hydroxyl and epoxy-hydroxyl groups, were prepared and blended with two different molecular weights of polyethylene glycol (PEG) for tribological investigation. Epoxy-hydroxyl-terminated rGO dispersed in PEG showed significantly smaller values of the friction coefficient. In this condition, PEG chains intercalate between the functionalized graphene sheets, and shear can take place between the PEG and rGO sheets. However, the friction…

• DO
  Department of Science and Technology, Ministry of Science and Technology, India
• II
  Indian Institute of Technology Madras
• JS
  Japan Society for the Promotion of Science
• JB
  Jacob Blaustein Center for Scientific Cooperation