Tribological properties of alkylated reduced graphene oxide as lubricant additive

As lubricant additive, graphene and/or graphene oxide (GO) has received considerable interest due to its excellent tribological performance. Here, grafting octadecylamine(ODA) onto GO via facile amidation was carried out and hydrazine monohydrate was used as reducing agent to attain ODA-RGO as lubricant additive. The physical, chemical properties and morphologies of ODA-RGO and GO were characterized.Tribological properties were evaluated using a ball-on-plate configuration on a UMT-3 tribometer and then worn surfaces were examined by Scanning electron microscope (SEM), Raman spectra and optical microscope. It was found that ODA-RGO was helpful for lubrication and friction-reduction under the applied load of 10 N. The excellent tribological behavior was contributed to the formation of ODA-RGO protective film which could avoid direct contact between tribological mates. The restacked shape of sheet-like ODA-RGO also plays an important role in friction process.