Hydroxide Ions Stabilize Open Carbon Nanotubes in Degassed Water
Résumé
The main hurdle preventing the widespread use
of single-walled carbon nanotubes remains the lack of
methods with which to produce formulations of pristine,
unshortened, unfunctionalized, individualized single-walled
carbon nanotubes, thus preserving their extraordinary properties.
In particular, sonication leads to shortening, which is
detrimental to percolation properties (electrical, thermal,
mechanical, etc.). Using reductive dissolution and transfer into
degassed water, open-ended, water-filled nanotubes can be
dispersed as individualized nanotubes in water−dimethyl
sulfoxide mixtures, avoiding the use of sonication and
surfactant. Closed nanotubes, however, aggregate immediately upon contact with water. Photoluminescence and
absorption spectroscopy both point out a very high degree of individualization while retaining lengths of several microns.
The resulting transparent conducting films are 1 order of magnitude more conductive than surfactant-based blanks at
equal transmittance.