Ultra-Strong Nanotube Composites

TheMatt writes "In a story that makes you say "Cool!", Nicholas Kotov and co-workers have created a nanotube composite material six times stronger than carbon-fiber composites. Their final product is a crosslinked material which appears to be just as strong as silicon carbide and tantalum carbide!"

Comments

Re:No big uses soon...

[Drishmung]

'strong' is a much overused word, and pretty meaningless without significant qualification. Which is stronger: Balsa wood or Teak? OK, so when was the last time you made a model plane out of teak then?

Materials have the following attributes (and others of course):

• brittle/tough (glass vs steel)
• elastic/inelastic (aka stiffness)
• isotropic/anisotrpic
• density
• tempera ture stability
• chemical stability (resistance to corrosion)
• cost of raw material
• cost of manufacture
• hardness

Now, stiffness is one of the important ones. High Young's modulus (stiffness) good, low Young's modulus bad. Stiff and light is better; stiff, light and tough really attracts attention.

For a very readable introduction to this, I recommend The New Science of Strong Materials (or why you don't fall through the floor) by J.E. Gordon, also his Structures.

Re:All the data you can't understand

[florescent_beige]

The notation they are using is (resin-type/fiber-type)subscript-number-of-layers so ((PEI/PAA)(PEI/SWNT)5)8 means one layer of polyethyleneimine and polyacrylic acid followed by 5 layers of PEI and Single Wall Nano Tubes with the whole shebang repeated 8 times for a total of 48 layers.

Checking out the stress-strain curves, the peak is around 160 MPa. A typical modern graphite composite might give you 4 or 5 times higher than that. It just goes to show that high fiber properties are just a portion of the final composite strength.

Another thing I notice about the stress strain curves is the non-linearity. It looks like there is some internal damage maybe happening in the material before failure. This is a concern for repeated loading (fatigue).