Carbon nanotubes future composite building?

[nieuwhout83]

A company called Fibermax Composites sells on it's website www.fibermax.eu a product called "multiwall carbon nanotubes". I never heard about this so called future composite. This is what they say about it:


Carbon nanotubes are the strongest and stiffest materials on earth, in terms of tensile strength and elastic modulus respectively. They are used as an additive or filler in composites (to increase strength in directions lacking reinforcement and prevent delamination), in electronics, optics, as a thermal or electrical conductor, and in many other fields of material science.
Directions for use in composites: Add 2-3% by weight to resin and mix well. Larger quantity will not improve nor worsen mechanical properties.


I wonder if adding this stuff on my epoxid resin before lamminating my carbon sandwich construction should improve strengh and stiffness.

When you Google on this material you'll find a lot of articles about it. Anyone tried it allready???

[marshmat]

The current generation of commercially produced nanotubes are extremely short, almost like a fibrous filler powder. There are a few companies mixing small quantities of them with epoxy, which they claim improves certain mechanical properties of the cured epoxy.

It's not easy to do, and without very careful engineering, there's no guarantee it'll work. If you have the financial resources and the engineering know-how, by all means play around with it; this is a field that could really use some R&D for practical applications. If you're more interested in making your laminate stronger and/or stiffer, and don't feel like dropping heaps of cash on nanotube powder, just switch to a higher quality carbon. If you're using a 3k weave right now, switching to a 12k biaxial will bring much more strength and stiffness for much lower cost than you'd get by messing with nanotubes.

Actual nanotube fabric, ie. continuous chains of the things, would be an order-of-magnitude improvement over the current generation of carbon fibre. But we don't have a clue how to make such fibres yet.

[Herman]

It seems to help about anything. Both in composites, but added to polishing pastes, it improves shine and cutting powder.

I have a small bucket of the material, but I would need to thoroughly rest things to make any claims.

One remark already: The material is so new that is has not been tested yet on carcinogenic properties, or at least there are no conclusions yet. As it is a fibrous material, and in a composition which the human body cannot decompose, it should be threated with suspicion, at least untill proven not carcinogenic.

[CDK]

For boat building anything that starts with "nano" is of no importance: it is a bit like building a large house with very small bricks.

The infinitely small carbon tubes have a great future in electronics once it is possible to align them on a substrate with a precisely controlled spacing. That way very efficient capacitors, batteries and photovoltaic cells can be produced.

Experimenting with nanotubes can be hazardous without good protection. They will penetrate gloves, skin etc. very easily and cannot be removed or dissolved.

[Herman]

Do a search for "nanotubes epoxy" on Google and some claimed useful applications pop up.

[STRIDE]

I have been working with nanotube infused composites for about a year now at HPMI ( www.hpmi.net ).

So far as structural effects: They make the part slightly more brittle. That's about it.
No significant gains in Young's Modulus or UTS. The problem with nanotubes is that their amazing nano-scale properties do not translate well into a larger scale.

"Actual nanotube fabric, ie. continuous chains of the things, would be an order-of-magnitude improvement over the current generation of carbon fibre."

This material is called buckypaper. The best buckypaper we make has to be aligned with a supermagnet and still cannot be used in a composite. CNT's have very low inter-facial bonding strength and the buckypaper is too dense to allow resin to permeate it.

Herman: Where on earth did you get a bucket of Nanotubes??? We buy ours for several hundred dollars a gram!

Be wary of any commercial "nanotube" product. Actual nanotubes cannot be sold on a commercial scale and even then, their properties will be dubious.

[Chris Ostlind]

Originally Posted by CDK

For boat building anything that starts with "nano" is of no importance: it is a bit like building a large house with very small bricks.

-CDK 2010

Now there's a big quote that will be saved for future reference. This is something on the order of a guy back in the 1940's saying out loud, "we'll never be able to make orbiting satellites from millions of these transistor things you see being developed. They're just too big."

When are we going to learn that broad sweeping statements have no place in a technology hungry world.

[Herman]

Hi Stride, thanks for the insight.

I got a couple of cans from a nice exotic lady at JEC show last year or so. She did not want to take them back to Japan / China.

[CDK]

Originally Posted by Chris Ostlind

Now there's a big quote that will be saved for future reference. This is something on the order of a guy back in the 1940's saying out loud, "we'll never be able to make orbiting satellites from millions of these transistor things you see being developed. They're just too big."

When are we going to learn that broad sweeping statements have no place in a technology hungry world.

No Chris. I admit I said it crudely but the word "nano" is mostly used in a commercial context to attract interest.

I am sure this technology has a great future once it is possible to line up these small tubes in a perfect matrix and use that to keep the electrolyte in a battery from depositing ions in locations they didn't originate from. That could add a digit to the battery's life expectancy, maybe even two.

What I meant was adding randomly oriented nanotubes to resin and build a boat with it. That only makes things more dangerous.

[RussellC]

Just out of curiosity.
A few years ago the CSIRO performed a successful experiment spinning CNT into continous fibres up to a metre long (they were limited in length by being hand drawn).

Experiments wuth the resultant thread showed it could be successfully woven and knitted without loss of strength.

Russell

http://www.csiro.au/science/Carbon-Nanotubes.html
http://www.csiro.au/science/Carbon-Nanotube-Yarn.html

[marshmat]

Originally Posted by marshmat

The current generation of commercially produced nanotubes are extremely short, almost like a fibrous filler powder. There are a few companies mixing small quantities of them with epoxy, which they claim improves certain mechanical properties of the cured epoxy.

It's not easy to do, and without very careful engineering, there's no guarantee it'll work. If you have the financial resources and the engineering know-how, by all means play around with it; this is a field that could really use some R&D for practical applications. If you're more interested in making your laminate stronger and/or stiffer, and don't feel like dropping heaps of cash on nanotube powder, just switch to a higher quality carbon. If you're using a 3k weave right now, switching to a 12k biaxial will bring much more strength and stiffness for much lower cost than you'd get by messing with nanotubes.

Actual nanotube fabric, ie. continuous chains of the things, would be an order-of-magnitude improvement over the current generation of carbon fibre. But we don't have a clue how to make such fibres yet.

This somehow attracted an anonymous red dot labelled "enough already". Let's stick to technical discussion out in the open, shall we?

Originally Posted by Herman

One remark already: The material is so new that is has not been tested yet on carcinogenic properties, or at least there are no conclusions yet. As it is a fibrous material, and in a composition which the human body cannot decompose, it should be threated with suspicion, at least untill proven not carcinogenic.

A very valid point, and I share your suspicions- especially in the light of what we know about existing microfibrous materials such as asbestos. Most labs I know are very meticulous in their handling procedures for nanotubes.

Originally Posted by STRIDE

So far as structural effects: They make the part slightly more brittle. That's about it.
No significant gains in Young's Modulus or UTS. The problem with nanotubes is that their amazing nano-scale properties do not translate well into a larger scale.

This doesn't surprise me; I doubt the CNTs you've managed to obtain are long enough to have any real structural impact. Too short, and they'll just act like a fibrous filler without much effect on strength. I don't know of anyone who is making CNTs that are long enough and in large enough quantities to be of significant structural benefit.... yet. That may change in a year (or two, or five...)

This material is called buckypaper. The best buckypaper we make has to be aligned with a supermagnet and still cannot be used in a composite. CNT's have very low inter-facial bonding strength and the buckypaper is too dense to allow resin to permeate it.

I don't see how buckypaper would be of much use, for exactly the reasons you describe. When we are able to produce CNTs with macroscopic lengths (on the order of centimetres or metres) and weave these into fabrics, that could lead to some major structural gains. For the moment, we're stuck at the scale of micrometres to nanometres, so trying to make anything out of them means we rely on the relatively weak bonds between adjacent tubes- not much use for structural fabrics.

Be wary of any commercial "nanotube" product. Actual nanotubes cannot be sold on a commercial scale and even then, their properties will be dubious.

Of course, that doesn't stop less scrupulous types from selling everything from shredded carbon fibre to graphite dust as "nanotubes" online...... and the horrifically expensive "nanotube enhanced" resins only contain very tiny quantities of the cheapest possible CNTs. They can be (and are) commercially produced, but only in small quantities of poor quality at tremendous cost.