An approach to the uniform dispersion of a high volume fraction of carbon nanotubes in aluminum powder
A slurry based process was developed to achieve the uniform dispersion of a high volume fraction of carbon nanotubes (CNTs) in aluminum powder. Al powder was subjected to surface modification to introduce a hydrophilic polyvinyl alcohol (PVA) membrane on its surface, which has good wettability and strong hydrogen bonding interactivity with functionalized CNTs. It was found that, when mixed with a CNT aqueous suspension, the PVA-modified Al (Al@PVA) powder resulted in much better adsorption uniformity of CNTs than the untreated Al powder. The adsorption capacity of CNTs was greatly enhanced by using nanoflake Al powder, which has better geometric compatibility with the CNTs and a larger surface area than spherical powder. Consequently, a uniform dispersion of 20 vol.% CNTs was achieved in the nanoflake Al@PVA powders. The advantage of this approach is that it provides easy control over adsorption uniformity and capacity of CNTs in a metal matrix, through the combination of surface modification and thickness adjustment of the metal flake powders.