Polymer Group Research

The ultimate polymer?

Nanotubes as polymers

A glance at the table below shows that nanotubes have the dimensions of molecules rather than of fibres. In combination with their modest flexibility (recently illustrated by Sano et al, through the formation of nanotube rings) and their atomistically specific structures, we should think of nanotubes as polymer molecules.
Diameter /nm
Carbon Fibres
~10000
Carbon Nanotubes (Multi-walled)
~10
Carbon Nanotubes (Single-walled)
~1
Tobacco Mosaic Virus
~10
Polymethylmethacrylate (PMMA)
~0.7

If nanotubes are polymer molecules they must belong the class of conjugated molecules that includes high performance mechanical polymers such as Kelvar and PBO as well as electically active materials such as polypyrrole and polyphenylene vinylene (Structures ). We can consider nanotubes to be the ultimate form of such materials because all the carbon bonds take part in the conjugation and contribute to the excellent properties. In addition we can expect that nanotubes will form a liquid crystalline phase that may be used to produce highly ordered structures, such as aligned fibres.
See our ROPA web final report for information on some of our previous work in this area.
We have found that even multi-wall nanotubes can  behave analagously to polymers in solution. One example is the formation of a viscoelastic gel as modest concentrations of around 5vol% in water:

Gel photo







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