Hydrothermal synthesized magnesium silicate hydroxide/graphene nanocomposites in a MgO-SiO2-graphite-H2O alkaline system and its application in anti-wear additive toward infinitesimal wear.

The paper describes a hydrothermal synthesis of one new-style inorganic modified graphene nanomaterial called magnesium silicate hydroxide/graphene (MSH/graphene) in a MgO-SiO 2 -graphite-H 2 O system, and reveals its tribological behaviors as additives in poly-alpha-olefin (PAO). These MSH/graphene nanocomposites consist of MSH and various forms of graphene evolved from natural microcrystalline graphite. Four-ball experiments indicate that MSH/graphene nanocomposites as additives in PAO display outstanding tribological performances and nearly eliminate wear despite a severe contact pressure of 3.91 GPa. This can be attributed to the attachment of graphene to MSH, enabling it to successfully enter the asperity clearances so as to bring into full play to graphene's extreme mechanical strength and/or forming a tribofilm consisting of nanocrystalline graphite and amorphous carbon (a-C) on the sliding surfaces. MSH/graphene nanocomposites were hydrothermally synthetized using graphite as one of the raw materials. This type of nanocomposites consist of MSH and various forms of graphene. Image 1 • MSH/graphene nanocomposites were hydrothermally synthesized using graphite as a raw material. • MSH/graphene consists of MSH and various types of graphene. • The slid surfaces lubricated with MSH/graphene-containing oil have infinitesimal wear under a pressure of 3.91 GPa. • Tribological tests confirm graphene competitively penetrate into the contact area and form a tribofilm. [ABSTRACT FROM AUTHOR]