Preparation of Ultrafine Carbon Tubes in Nanochannels of an Anodic Aluminum Oxide Film

A template carbonization technique was applied to prepare carbon nanotubes and submicron-tubes in one dimensional channels. An anodic aluminum oxide film that has uniform and straight channels with a diameter at the nanometer level was used as a one-dimensional template. The pyrolytic carbon deposition on the channel wall was carried out by exposing the anodic oxide film to propylene at 800 °C. The carbon was then liberated from the anodic oxide film by HF washing. It was found that the resultant carbon is comprised only of uniform hollow tubes with open ends. The infiltration of poly(furfuryl alcohol) into the channels of the film followed by heat treatment led to the formation of bamboolike carbon tubes. For all the carbon tubes obtained here, the outer diameter (30 or 230 nm) and the length (60 or 75 μm) precisely reflect the channel diameter and the thickness of the template used, respectively. Furthermore, in the case of the carbon tubes from propylene, the wall thickness of the tubes was easily controllable by changing the carbon deposition period.