Al(OH)3/multiwalled carbon nanotube composite:: Homogeneous coverage of Al(OH)3 on carbon nanotube surfaces

Carbon nanotube (CNT) based composite materials were obtained by covering the surface of multiwalled carbon nanotubes (MWCNTs) with alumina. The coverage material was prepared by either thermal or chemical decomposition of aluminum sources, such as aluminum trichloride (AlCl3) and aluminum isopropoxide (AlIP). To vary the interaction between the hosting CNTs and the coverage material, MWCNTs were treated with and without surfactants. The direct impregnation technique was found to be successful in the case of AlIP, whereas an adsorbed layer of surfactant provides a better interaction in the case of AlCl3 via their. ionic groups. With the latter method, MWCNT-based alumina composites were obtained with a homogeneous coverage never observed before; transmission electron microscopy corroborates these conclusions. By means of energy-dispersive X-ray analysis and X-ray photoelectron spectroscopy, the coverage was identified to be partly Al2O3 but predominantly AI(OH)(3), which starts to convert to Al2O3 at 200 degreesC.