Directional Carbon Nanotube Thin Films On The Porous Anodic Alumina Template And Tribological Study

Upon the application background of solid lubricants and wear resistant materials, themicrostructure and tribological property of carbon nanostructure synthesized on the porous anodic aluminium oxide (AAO) template were investigated. The preparation parameters of both the porous AAO template and carbon nanostructure synthesized on the template were obtained. The tribological properties of the film of well-aligned carbon nanotubes synthesized on the porous AAO template at relatively low loads were also evaluated.Under room temperature, the porous AAO template with pores distributed uniformly could be synthesized by a two-step anodization technique in oxalic acid. The microstructures of the porous AAO template were systematically investigated characterized by atomic force microscopy (AFM) and scanning electron microscope (SEM). The differences between the porous AAO templates prepared by one-step and by two-step anodization were also studied. The effect of erosion time in phosphoric acid on the microstructure of the porous AAO template was investigated in detail as well.Co and Fe-Co alloys could be deposited in the porous AAO template by using alternating current. Carbon nanofibers, well-aligned carbon nanorods and alignend carbon nanotubes could be synthesized on the porous AAO template with catalysts by chemical vapor deposition method. The morphology of Co and Fe-Co alloys deposited in the template and the microstructure of the carbon nanostructures synthesized on the template were systematically investigated by means of SEM, TEM, EDS and Raman spectrum. The growth mechanisms of carbon nanostructures were also studied in detail, it was found that the catalysts and their distributions that made the decision on the final carbon nanostructures.The friction tests of the film of the aligned carbon nanotubes were performed using a block-on-ring friction tester and using friction force microscopy (FFM) and atomic force microscopy (AFM). The effect of sliding velocity on the friction force was investigated at a low applied load. It was found that the friction force reduced when the sliding velocity increased under a relatively low applied load. The friction properties of the aligned carbon nanotube filmwere very uniform in test region. The film on AAO template had a considerable self-lubricating effect and the friction coefficient of the film was only 0.082.In conclusion, the aligned carbon nanotube film synthesized on the porous anodic aluminium oxide template shows the excellent friction property and potential applications as solid lubricants and wear resistant materials.