Long-term stably dispersed functionalized graphene oxide as an oil additive

Abstract

T154 modified graphene oxide as an oil additive exhibited excellent tribological properties, long-term stable dispersity and high thermal properties.

Tribological Performance Investigation of a Commercial Engine Oil Incorporating Reduced Graphene Oxide as Additive

“…This result confirms the existence of a protective coating on the rubbing surfaces, due to the rGO additive, which provides a more effective lubrication between the sliding parts. Therefore, it is apparent that rGO plays a key role towards the diminution of friction and the wear track reduction, contributing to surface protection against shear stress through the delamination effect [ 20 ].…”

“…This result confirms the existence of a protective coating on the rubbing surfaces, due to the rGO additive, which provides a more effective lubrication between the sliding parts. Therefore, it is apparent that rGO plays a key role towards the diminution of friction and the wear track reduction, contributing to surface protection against shear stress through the delamination effect [20]. SEM images (Figure 6) supported by energy-dispersive X-ray spectroscopy (EDS) (Figure S5) of the reference and the rGO6 samples were undertaken to investigate the degree of deformation of the rubbing surfaces, and the extended presence of carbon originating from rGO through EDS mapping.…”

“…Hence, long-term stability still remains challenging towards the formulation of highly efficient and reliable nanolubricants in order not to settle down after a long time of storage, ensuring negligible mechanical failure (wear) between worn surfaces [16,19]. Indeed, the most relevant studies report on a critical concentration of graphenebased additives in lube oils ranging from 0.01% to 1%, which sustains a tradeoff between COF improvement and long-term stability [10,[20][21][22][23]; the optimum concentration varies depending on the nature of the graphene based additive, such as variation of functional groups, number of layers, flake size and the type of the sliding contacts [24]. An extensive investigation on the relative factors to improve the stability of lube oils incorporating nanoparticles is imperative in order to produce highly efficient lubricants that can reduce friction and mechanical failure between worn surfaces, which are considered as the main causes of energy dissipation in automobile engines.…”

Chemically functionalized graphene oxide with N‐phenyl‐p‐phenylenediamine as efficient tribo‐ and rheological modifier for lubricating oil

“…17 Certainly, recent studies have reported that the graphene-based additives in lubricating oil with varying concentrations ranging from 0.01% to 1% show significant improvement in COF and stability for a longer duration of time. [18][19][20][21] Berman et al 22 studied the antiwear property of graphene using steel tribo pair and found that chemical interactions provide good tribological properties. Lin et al 23 done the chemical modification of graphene using stearic acid/ oleic acid and found that the friction coefficient and antiwear performance were extensively improved with modified graphene.…”

“…Thus, the long‐term stability of the nanolubricant remained challenging for the formulations due to the settling down of the nanomaterials in the lube oil after prolonged storage 17 . Certainly, recent studies have reported that the graphene‐based additives in lubricating oil with varying concentrations ranging from 0.01% to 1% show significant improvement in COF and stability for a longer duration of time 18–21 . Berman et al 22 studied the antiwear property of graphene using steel tribo pair and found that chemical interactions provide good tribological properties.…”