ABSTRACT
As-produced single-walled carbon nanotubes (SWCNTs) are bound together in very thick bundles of a few hundred tubes by very strong van der Waals interactions.1-4 These bundles can be tens of nanometers in diameter, many micrometers long, and tend to exhibit properties that are distinctly inferior to those of individual carbon nanotubes (CNTs).5, 6 As for multi-walled carbon nanotubes (MWCNTs), they are usually highly entangled when produced by “conventional methods”.7 Because of this tendency to remain bundled even if attempts are made to disperse them, the production of stable dispersions of individual or very thin bundles of SWCNTs in (super) acids,8, 9 water,10-14 or organic solvents15-20 remains a challenge. The realization of such dispersions, which enables the CNTs to achieve their full potential, is a prerequisite for their further application, such as making CNT network transistors21 or biosensors,22 (potential future) drug delivery systems,23 or for enabling the incorporation into a polymer matrix.24, 25–Š‡ϐ‹‡Ž†‘ˆȀ’‘Ž›‡”ƒ‘…‘’‘•‹–‡• in particular, achievement of a uniform dispersion of CNTs is highly preferable. For example, the presence of bundles reduces the
‡ơ‡…–‹˜‡‡••ƒ•ƒ”‡‹ˆ‘”…‹‰ƒ‰‡–26 or as an electrically conductive ϐ‹ŽŽ‡”ǡ27 and it increases the value of the percolation threshold of nanocomposites.28
