Expert: George Maxwell - 9/4/2007

Question
I have recently discovered that carbon fiber sheets are not exceedingly difficult to work with. I never thought one could make home built bike frames, car parts, boats and other things. The only thing is Carbon Fiber is expensive.  When I was a kid, Mr. Wizard (Don Herbert, I am sure you know who he is, but just in case you don't, see this link.  [     http://en.wikipedia.org/wiki/Mr_wizard     ])  Mr. Wizard made nylon threads in his kitchen with two liquids. My question is how hard would it be to produce carbon fiber strands, what does the manufacturing process entail? The nylon reference is there to illustrate my belief that not everything has to come from a factory as long as you know how. Carbon is everywhere right? I exhale carbon. I recently read that when the chemicals of primordial Earth where brought together along with electricity, both amino acids and carbon where produced. With so much carbon everywhere and if there isn't any tools or complicated procedures involved I should be able to make carbon fiber strands just like some factory.

Thank you
Colin Schabel
Charleston, South Carolina


Answer
Thanks for a great question, and I'm really glad to meet another Mr Wizard fan!

I'm sure that it's possible to make some form of carbon fiber without being in a factory, but the thing is that (although there's carbon all around us) its the way carbon  is put together that determines the properties of the bulk material.

For example, both Graphite and Diamond are pure carbon but because the carbon atoms within them are arranged differently, they have very different appearences and properties. In essence what your question is trying to do is to turn one form of carbon in to another -like turning graphite to diamond: difficult!

To take one of the sources of carbon you mention (breathing out), you're breathing out carbon dioxide: to get even impure carbon, you'd have to react your breath with burning magnesium and collect the soot that forms, and even then, lumps of soot aren't what we need.

To make carbon fiber in industry, you don't start with pure carbon at all, you start with a plastic called Polyacrylonitrile (PAN to its friends). PAN is made up of long strands of carbon atoms with little bits of other materials hanging off the side. Heating up the PAN under carefully-controlled conditions breaks off all the other material and causes the strands of carbon atoms to bind together - Carbon Fiber.

If you had the right gear, you might just be able to do this in the garage, but the cost would be massively above just paying for new Carbon Fiber. Given the impure sources of carbon that we have available at home, it's unlikely that (using our current knowledge) we could make a useable carbon fiber, and certainly not economically.

That's not to say it's not a good area for research! Part of my current job involves looking at ways to make plastics from chemicals extracted from vegetables. At the moment, we can make plastics like those used in soda bottles, but if we find a way to make PAN from, say, vegetable oil, we'd be much closer to "homemade carbon fiber".

Thanks again for a great and thought-provoking question.