Saturday, 5 March 2011

Carbon nanotubes - why they are so cool!

A Carbon Nanotube (CNT) is  50,000 times narrower than a human hair. It is 200 times stronger than steel, light as air and more flexible than rubber. It is transparent, conducts electricity, retains its properties in temperatures cooler than liquid nitrogen or hotter than the melting point of iron, and is highly impermeable - not even helium gas can get through it. 


Nanotubes are made out of graphene. "Graphene (a thin sheet of carbon atoms) is the strongest material ever measured ... it would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of cling film" [1]
Nanotubes are being tested for use in so many spheres from sporting equipment to medicine to military defence so I've been trying to gather together all the very coolest things about CNT's.

Here is my list so far:
- Stretchy Loudspeakers - Transparent, flexible loudspeakers are tens of nanometers thick and just plain cool!
- Cloth Batteries - (E-shirts) You'll be able to charge up your phone from your clothes. 
- Super Body armour - Combat jackets that use CNT fibers to stop bullets and to monitor the condition of the wearer- -
- Super strength muscles (like superman):
- A Spiderman suit - so that soldiers can walk up walls 
- Nanotube computers - ultra-fast electronics of the future - 
- Cheap drinking water from the ocean.  - CNT membranes can aid in filtration. This can purportedly reduce desalination costs by 75%. The tubes are so thin that small particles (like water molecules) can pass through them, while blocking larger particles (such as the chloride ions in salt).
Ever lasting Solar Cells - Nanotubes used to make self fixing solar cells
- Air pollution filter—CNT membranes can filter carbon dioxide from power plant emissions.


How to make your own Nanotube:
1. Take a pencil and using some adhesive tape, extract a thin layer of carbon - be careful because you need to end up with a small sheet of graphene just one atom thick - oh, and you might need to remove any clay, wax or charcoal that you find mixed in with the carbon.(this video shows how)
2. Roll up the graphene carefully into a seamless cylinder, e voila!.

Obviously, a pencil is very brittle, but thats because its not pure carbon like graphene, coal or a diamond.

The main barrier to our nanotube future is that they still haven't found an easy way to mass produce them, so for now we only have prototypes and lots of excited scientists.


A technical definition of a Carbon Nanotube:
"Conceptually, single-wall carbon nanotubes (SWCNTs) can be considered to be formed by the rolling of a single layer of graphite (called a graphene layer) into a seamless cylinder. A multiwall carbon nanotube (MWCNT) can similarly be considered to be a coaxial assembly of cylinders of SWCNTs, like a Russian doll, one within another; the separation between tubes is about equal to that between the layers in natural graphite. Hence, nanotubes are one-dimensional objects with a well-defined direction along the nanotube axis that is analogous to the in-plane directions of graphite." —M. S. Dresselhaus, Department of Physics and the Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology source: http://www.nanotech-now.com/nanotube-buckyball-sites.htm

No comments:

Post a Comment

Speed Learning Guitar

Practising the guitar is all about getting better at it. Repetition is necessary but repeat too much and progress can stop, as I found out. ...