Dispersion and shortening of multi-walled carbon nanotubes by size modification

The shortening of multi-walled carbon nanotubes (CNTs) was achieved by size-reduction treatment using shear force. Special atomizing unit with double diamond disks under a higher forwarding speed of CNTs suspension was used to obtain a high shear force and to break the entangled CNTs. Tangled pristine CNTs can be shortened below 200 nm by the introduction of shear stress during repetitive size-reduction treatment. CNTs that have undergone size-reduction treatment show a lower optical transmittance than that of the original untreated CNTs, resulting in the well dispersion in aqueous suspension.