Carbon nanotubes comprise a class of materials that possess
a remarkable ensemble of physical properties: they are stronger
than steel, flexible, and are excellent electrical and thermal
conductors. They are therefore the subject of world-wide development
efforts for diverse applications including such sensors, nano-electronics,
ultra-strong fibers, and high current conductors. Realization
of these applications has been hindered by the difficulty in
obtaining and manipulating pure nanotubes. Our program seeks
to develop fluidic methods that accomplish the necessary processing
tasks needed for applications. The current focus is on assessing
the quality of dispersion through neutron scattering, developing
separation techniques through chromatography and orientation
through flow.
Objective
To develop techniques, such as chromatography, for the dispersal
and separation of single wall nanotubes to produce NIST Reference
Materials.
NIST Role
According to the National Nanotechnology Initiative, a priority
research need is “Metrology for Liquid-Phase Manufacturing
of Nanomaterials. Specifically mentioned is the need for Scattering
from nanotubes, effects of flow, and metrology for length,
diameter, chirality and electrical properties. Our program dovetails
with these needs:
Scattering techniques are used to provide definitive measures
of dispersion.
Chromatography for separation of tubes and measurements
of their size and structure.
Flow based control; measures of orientation and conductivity.
Assess the potential of a Reference Material
Highlights
CNTs as Processing Additives
Elimination of Die-Swell
Scattering and Separation
Flow induced orientation
Customers and Impact
Characterization of SWNT dispersion
Methods of improved SWNT Fractionation
Methods of improved SWNT alignment
Modeling and measuring nanotube interactions in suspensions
and melts for predicting dispersion, structure, and directed
self assembly into two and three dimensional hierarchical
structures
Optical properties of aligned SWNTs
Using SANS to develop a measurement protocol for quantifying dispersion, orientation and structure in SWNT suspensions and nanocomposite melts
Dispersion and characterization of DNA wrapped SWNTs for bio-sensor applications
NIST Contributors:
B. Bauer, M. Becker, B. Blair, J. Douglas
E. Hobbie, S. Kharchenko, K. Migler
Collaborators:
DuPont Chemical
Rice University
University of Kentucky
Michigan Tech
Processing Characterization Group
Polymers Division
Materials Science and Engineering Laboratory
