Humidity effects on tribology of advanced carbon materials

In micro and nanotribology, most exciting materials will be advanced carbon materials. These include carbon nanotubes (CNT), fullerene C60, onionlike carbon and diamondlike carbon. However, tribology study on these materials started in the late 1990s, limited information of the influence of environmental atmosphere on tribology being available. The effect of relative humidity (RH) on micro and nanotribology of advanced carbon materials as well as well-known lamellar materials such as highly oriented pyro-graphite, molybdenum disulfide and mica has been studied. At high RH, friction and adhesion became high. All the materials except vertically aligned (VA) CNT showed RH dependence of friction. The primary reason for none of RH dependence of VACNT is the super hydrophobic property.