Surface modif ication of carbon nanotubes by plasma polymerization

The ult ra-thin films of pyrrole and polystyrene were deposited on the surfaces of the multi-wall carbonnanotubes (MWNTs) using a plasma polymerization method. The high resolution t ransmission elect ron microscopy( HRTEM) images show a 7 nm thickness polymer layer has been uniformly deposited on the outer surface of theMWNTs , while an only 1～3 nm polymer layer was deposited on the inner surface. MWNTs coated with polystyrene and uncoated were added into the polystyrene mat rix , respectively. Transmission elect ron microscopy ( TEM)analysis reveals that the MWNTs coated with the polystyrene are well-dispersed in the polystyrene mat rix. The mechanical test s result s show that the well-dispersed MWNTs can effectively enhance the tensile st rength and modulusof the composites.