ALUMINUM COATED CARBON NANOTUBES TISSUE VIA AN ELECTRODEPOSITION FROM AN ORGANIC NON-AQUEOUS MEDIUM

Electrodeposition of aluminum (Al) on carbon nanotubes (CNT) tissue was studied. The procedure was performed in an organic non-aqueous solution of ethylbenzene containing aluminum bromide (AlBr₃) and potassium bromide (KBr) salts. Electrochemical impedance spectroscopy was conducted to estimating the resistance of CNT tissues, and their pristine electrical behavior as well as subsequent to theirs impregnation in the electrolytic bath. Cyclic voltammograms and potentiodynamic curves were recorded in order to attain a better comprehension of the system, and to assist defining the optimal conditions for the electrodeposition. The effects of the experimental parameters on the process and the final coating were explored.

The morphology of Al coatings was characterized by high resolution scanning electron microscope (HR-SEM). The deposited layer is uniform, and composed of crystals exhibiting indentations faceted likewise. Cathodic polarization of the substrate was evaluated as a possible pretreatment and was found to enable the formation of coatings with higher density. The Al coating is very delicate; it is soft, prone to fractures, and not well adhered to the substrate. When deposition currents exceed a certain limit, growth occurs in a different manner, and results in dendritic deposits that tend to disintegrate readily. Nonetheless, this process facilitates production of light CNT tissues being coated with a pure thin film of Al from both sides, while maintaining their flexibility, and as such it constitutes the first step toward a wide variety of new possibilities.