Atomic layer deposition onto carbon fiber: From single layer deposition via multilayer structure to metal oxide microtubes

Layers of alumina, titania and double layers of alumina/titania (and reverse) were deposited onto bundles of carbon fibers in an atomic layer deposition process. Scanning electron microscopy (SEM) images of the coated carbon fibers revealed that each fiber of a bundle was coated homogenously and separately and that no bridges were formed between the fibers. Transmission electron microscopy and SEM images showed that the coating was confomial, uniform, had a good adhesion to the fiber surface and that the morphology of the coating surface was similar to that of fiber surface. In case of double layers, the average deposition rate of coatings did not depend on the sequence of layer deposition. After coating, the carbon fibers were selectively removed by thermal oxidation in air at temperatures of 550 degrees C and 900 degrees C, leading to metal oxide microtubes. (C) 2013 American Vacuum Society. [http://dx.doi.org/10.1116/1.4768917]