Hard Carbon Spheres as Micro-Bearings for Water-Based Lubrication

Lubricants play an integral role in the operation of several technologies and in biology, ranging from moving parts in machinery to the biolubrication of articular joints. We have found that an easily synthesized system of monodisperse hard carbon submicron spherical particles coupled with a surfactant coating results in an effective water-based lubricant that has frictional coefficients that start approaching those of synovial fluids. Friction forces are measured at varying applied loads between two borosilicate surfaces using a commercial tribometer with different formulations (i.e. varying concentrations of surfactant, carbon particles) of the new lubricant. The novel water-based lubricant formulation is a potential alternative to conventional oil-based lubricants.