Nanotube composites

A paper, “The extraordinary reinforcing efficiency of single-walled carbon nanotubes in oriented poly(vinyl alcohol) tapes” recently published has this exciting abstract:

“This paper reports on oriented poly(vinyl alcohol)/single-walled carbon nanotube (PVA/SWNT) tapes that were prepared by a mild processing route, involving the use of dimethyl sulfoxide (DMSO) as a solvent. Composite films with homogeneously dispersed SWNTs were cast from solution and drawn into oriented tapes using solid-state drawing. The obtained tapes showed the extraordinary reinforcing effects of the SWNTs, as the addition of 1.0 wt% SWNTs tripled the tensile strength of the PVA tapes. Micromechanical analysis showed that the nanotube contribution to the composite strength was as high as 88 GPa, which is very high when compared to other data reported in the literature, and for the first time begins to exploit the theoretical strength of nanotubes.”

The exciting, operative number, of course is “88 GPa”.  Now I know that this doesn’t mean that they’ve created a structure which has a tensile strength of “88 GPa”, but it does show how carbon nanotube developments are proceeding at an ever increasing pace.

You can get the full paper, but you either have to be a member of IOP or pony up $30.00 as a guest to read it. 

An article on talks about this development.  However, I’m not sure where they get the statement; “The work shows for the first time the true reinforcing potential of single-walled carbon nanotubes (SWNTs) with effective properties of nanotubes in composites, which are close to their theoretical values.”  The theoretical limit of carbon nanotubes is, I believe, ~300GPa, not the 88 GPa discussed in the article.  But never mind all that – this is still a very exciting development.

(Hat tip to reader Yakov for pointing out this development)

4 thoughts on “Nanotube composites

  1. Blaies Gassend

    It seems from the quote that 88 GPa is the stress in the nanotubes that make up the composite, not the stress in the composite, which I imagine is much lower.

  2. Jorge

    Of the top of my head Im not sure, but does anyone have the theoretical acceptable limits for the elevator. I suppose the question is, does anyone know the weight to stress ratio needed for the tether?

  3. Ted Semon Post author

    The number we’re looking for is ~60 GPa – this is theoretically strong enough to build the tether needed. However, this provides now safety factor (it’s barely strong enough) so, to provide a safety factor of 2, the ‘magic number’ is 120 GPa.

  4. Steel

    A while back I estimated this nano-films strength to be approximately 1 GPa (100-200 ksi). Currently, the strongest ‘real world’ length of material is approximately 5 GPa (700 ksi) — 2006 Team Astroaraneae Tether…which is still an Order of Magnitude shy of what’s necessary to build an actual Space Elevator.

    The pearl to be taken from this research is the usable strength of CNTs may be as high as 88 GPa, if not more. This is a good sign for those who would like to use materials this strong. So the moral of this story is…support your Tether Development Teams !!

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