Abstract Submitted to the    NANOTUBE'04 Conference:

Graphite and layered material made from metal disulphides (MoS2, WS2) are known to be very good lubricants. The weak bond strengths between the layers allow for easy shearing of the crystal, resulting in a lamellar mechanism of lubrication. Therefore they are widely used as solid lubricant or as additives dispersed in oil. However, the use of these additives is at the origin of some problems of toxicity and pollution. Recently, the application of nanoparticles and nanotubes in tribology has received considerable attention. The reason comes from the chemical stability of these spherical and cylindrical crystal shapes (absence of dangling bonds) in contrast to flat geometry. In this paper, we describe the tribological performances of some carbon and Mo-S-I nanotubes used as additives in lubricating oil. Our results show that nanotubes are potential additives for lubricating oil. They can be used as friction modifiers and/or antiwear additives in lubricating oils. The wear and friction characteristics of the pure oil can be significantly enhanced by dispersing only 1 wt % nanotubes. Such improvement is due to the formation of a deposit film in the contact area (DLC like coating and MoS2 respectively for carbon and Mo-S-I nanotubes) which reduce the frictional force.