Carbon Microspheres as Ball Bearings in Aqueous-Based Lubrication

Abstract

We present an exploratory study on a suspension of uniform carbon microspheres as a new class of aqueous-based lubricants. The surfactant-functionalized carbon microspheres (∼0.1 wt %) employ a rolling mechanism similar to ball bearings to provide low friction coefficients (μ ≈ 0.03) and minimize surface wear in shear experiments between various surfaces, even at high loads and high contact pressures. The size range, high monodispersity, and large yield stress of the C(μsphere), as well as the minimal environmental impact, are all desirable characteristics for the use of a C(μsphere)-SDS suspension as an alternative to oil-based lubricants in compatible devices and machinery.

Facile one‐pot method of initiator fixation for surface‐initiated atom transfer radical polymerization on carbon hard spheres

“…In addition, polymer‐grafted CHSs can be optimized for dispersions with a range of liquids, enabling their use as “nano‐ball bearing” additives for lubricants . The hardness and chemical robustness of the polymer‐grafted CHSs, in addition to their small but uniform size, should yield a high performance lubricant with enhanced resilience at both high temperatures and high pressures …”

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

“…Some examples of nano-objects in liquids and their reported sizes, for friction and wear reduction, with studies carried out on the macroscale, are as follows: WS 2 platelets (0.5 µm) in commercial mineral oil [16], ferric oxide nanoparticles (20–50 nm) in 500 solvent neutral (SN) mineral oil [17], spherical MoS 2 (15–60 nm) in poly-alpha-olefin (PAO) and 150 SN [18], spherical WS 2 nanoparticles (50–350 nm) in SN 150 and SN 190 [19], spheroidal carbon-nano-onion nanoparticles (<10 nm) in PAO [20], WS 2 nanoparticles (120 nm) in paraffin oil [21], MoS 2 spheres (0.5–3 µm) in 500 SN oil [22] and carbon spheres (420 nm) in water [23]. Mechanisms for friction and wear reduction have been reported as tribofilm formation, rolling, sliding, and reduced contact area.…”

Synergistic Effect of MoS2 and SiO2 Nanoparticles as Lubricant Additives for Magnesium Alloy–Steel Contacts

“…However, the poor stability of these additives during the process of applications does not meet the demands of new generation mechanical devices [ 11 ]. Additionally, the use of chlorine and phosphorus containing compounds is currently the focus of environmental concerns [ 12 ]. As a result, there is continuous research for the investigation of environmentally acceptable and efficient lubricant oil additives [ 13 ].…”