Aligned carbon nanotube/polymer composite film with anisotropic tribological behavior.

A general method had been developed to prepare highly aligned carbon nanotube/polymer composite films, which represented the first composite material with an anisotropic tribological property on the surface. The friction coefficient in the transverse direction was about 2 times of that of longitudinal direction. In addition, the aligned nanotubes provided the composite film with excellent electrical, mechanical, and thermal properties. This work also presented an efficient paradigm to synthesize friction materials with an anisotropic tribological behavior by introduction of one-dimensional nanostructures.