Enhanced Tribological Performance of Aminated Nano-Silica Modified Graphene Oxide as Water-Based Lubricant Additive

Abstract

Improving the tribological properties of water by adding nanomaterials as water-based lubricant additive has garnered increasing interest for the great potential in range of water-based applications. However, combining ideally two-dimensional layered nanomaterials and zero-dimensional nanoparticles to create synergistic enhancement of lubricating performance under water is still challenging. In this paper, a novel nanomaterial named aminated silica modified graphene oxide (SAG), which combines the layered nanomaterial graphene oxide (GO) and the nanoparticles hydrophilic nanosilica (SiO2) by 3-aminopropyltriethoxysilane (APTES), has been synthesized. The tribological properties of the SAG nanomaterial as additives in deionized water (DI water) are evaluated on a CSM tribometer under high contact pressure. Using the SAG nanomaterial in DI water, besides the very low friction coefficient it produces, dramatically reduces the wear rate of the wear track and especially the ball. More importantly, the SAG nanomaterial outperforms the individual GO and nanosilica in improving wear resistance. The SAG can also prevent the diamond like carbon (DLC) films deposited on the steel substrates from tearing. It is suggested that the excellent mechanical property of GO nanosheets and the microscopic ball-bearings effect of silica nanoparticles, on which is the SAG nanomaterial based, account for the lubricating and antiwear action. As water-based lubricant additives, this novel nanomaterial showing excellent tribological properties is believed to be a potential candidate for water-based lubrication.

Controllable synthesis of different morphologies of CuO nanostructures for tribological evaluation as water-based lubricant additives

“…At the optimum concentration (0.80 wt%), the nanoadditives filled the valleys within asperities, and formed a fine lubricating film which prevented the friction pairs from direct contact, leading to a reduced friction coefficient. Above the optimum concentration, random aggregation occurred on the surface of the friction pairs, which was higher than the thickness of the water film in the contact region and this caused abrasive wear, resulting in an increased friction coefficient [10,36,[53][54][55]. Variations of friction coefficient with sliding time are presented in Fig.…”

“…Many nanomaterials are beneficial for improving tribological properties of water-based lubricants [6][7][8]. Graphene and graphene oxide [9][10][11], carbon dots [12], hard carbon spheres [13], carbon nanotubes [14], ionic liquids [15], sulfides [16][17][18], oxides [2,7,19], and metal nanocopper [20,21] have been designed and synthesized to improve the performance of water. Furthermore, a number of lubrication mechanisms have been proposed to explain the improvement of tribological performance, including: (a) formation of physical or/and chemical tribofilms.…”

A Comprehensive Review of Water-Based Nanolubricants

“…Over the past few years, much research has been conducted on graphene-based composites including GO/SiO 2 [19,83], GO/TiO 2 [84], and GO/Al 2 O 3 [21]. For example, Huang et al [19] synthesised GO/SiO 2 water-based lubricants by mechanical stirring the aqueous suspension at 25 • C for 30 min, followed by ultrasonic processing (450 W) for 60 min (on/off interval of 5 s) in a chilled water bath.…”

Water lubrication of graphene oxide-based materials

“…SiO 2 has a long history as a lubricant, and the application of GO-SiO 2 composites in water lubrication is reported recently. Guo et al [70] synthesized a novel nanomaterial combining GO with 3-aminopropyltriethoxysilane (APTES)-modified SiO 2 (Fig. 5).…”

“…The schematic diagrams of the synthesis and tribological test of silica modified GO. Reproduced with permission from Ref [70],. © American Chemical Society, 2020.…”