High volume fraction and uniform dispersion of carbon nanotubes in aluminium powders
A slurry-based powder process was developed to disperse a high volume fraction of carbon nanotubes (CNTs) in aluminium (Al) powders. In this process, Al nanoflake powders with a high surface area were used and the powder surface was modified by polyvinyl alcohol (PVA) hydrosol before being mixed with CNTs aqueous dispersion. The PVA modification resulted in the formation of a hydrophilic membrane on the Al surface, which enhanced the water wettability and makes the surface property of the Al powder more compatible with that of the CNTs. Furthermore, the PVA membrane forms relatively strong bonds with the CNTs and prevent them from agglomeration during subsequent processing. Consequently, a high volume fraction and uniform dispersion of up to 10 vol CNTs was achieved in the Al nanoflake powders.