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 , order, polymer , 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