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Full Record for Micrograph 561

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Micrograph no
561
Brief description
Ordered film of carbon nanotubes
Keywords
alignment, carbon, carbon nanotube, dispersion, film, nanotube Link to MATTER Glossary entry for nanotube, order, polymer Link to MATTER Glossary entry for polymer, suspension Link to MATTER Glossary entry for suspension
Categories
Polymer
System
Carbon nanotube
Composition
Not specified
Standard codes
Reaction
Processing
A dilute (<0.3 vol%) suspension of nanotubes is filtered through a 0.2 mm membrane to form a solid film.
Applications
Carbon nanotubes may be considered a high performance mechanical polymer or an electrically conducting polymer but their greatest potential is in gas storage or as a filler in polymeric materials
Sample preparation
Solid nanotube films were prepared by filtration onto a 0.2 mm membrane filter under 0.6 bar negative pressure
Technique
Field emission gun scanning electron microscopy (FEGSEM)
Length bar
400 nm
Further information
It is necessary to form a stable dispersion of nanotubes in order to properly integrate them into polymeric systems. This can be achieved by treating them with acid to oxidise the tube surfaces. The tubes will then spontaneously disperse in an aqueous medium. The viscosity of these suspensions is analogous to that of polymers; it increases gradually with concentration up to a critical point (at about 0.7vol%) where entanglement occurs. A solid nanotube film has been formed by filtering the suspension through a 0.2mm membrane filter. Suspensions of relatively high concentration (>0.3vol%) yield films with random tube orientations but at lower concentrations (as in this sample), liquid crystal aggregation occurs and there is noticeable mutual alignment. The films exhibiting such alignment are tougher. This image was taken using a field emission gun scanning electron microscope (FEGSEM).
Contributor
Prof A H Windle
Organisation
Department of Materials Science and Metallurgy, University of Cambridge
Date
03/10/02
Licence for re-use
Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales