PHILADELPHIA – Researchers at the University of Pennsylvania
have devised a new method for aligning isolated single wall
carbon nanotubes and, in the process, have created a new kind of
material with liquid crystal-like properties, which they call
nematic nanotube gels. The gels could potentially serve as
sensors in complex fluids, where changes in local chemical
environment, such as acidity or solvent quality, can lead to
visible changes in the gel's shape. The researchers describe
their findings in the current issue of Physical Review Letters.
Single wall carbon nanotubes have astounded researchers with
their remarkable strength and their ability to conduct heat and
electricity. For many of their potential applications, however,
these nanotubes work best when they are aligned parallel to one
another, without forming aggregates or bundles. In solutions
with low concentrations of single wall carbon nanotubes, the
nanotubes are isotropic, or not oriented in a particular
direction. If the concentration of the s