The Blackest Black on Earth... Man-Made Black Hole!!!

[Clifford]

I heard about these Carbon Nanotubes on NPR... and then found them on the Net:

http://www.abc.net.au/science/articles/2008/01/16/2139711.htm

According to the article, the carbon nanofibers absorb 99.95% of the light.  

Presumably also non-visible wavelengths, but they didn't specify having tested UV, Infrared, and Microwaves.

If it could be made into a paint, it would be excellent for solar absorption.

Perhaps something similar will also be incorporated into the next generation of solar-electric too.

[adobejoe]

This is very neat. I would like to learn more.  What is the chemical composition, is it tradenamed, patented, organic, or inorganic.

Eager for more!!!

AdobeJoe

[clarsondd]

What is the chemical composition,

a carbon nanotube is made out of carbon (and a very small amount of unwanted impurities, > .01%)

is it tradenamed,

there are numerous suppliers, i don't know if any have become that well known.  

don't know if you would count buckyball as a trade name.

patented,

it consists of 100% carbon, it would be like trying to patent graphite or diamonds

although the manufacturing process probably is.

although, they are usually produced via chemical vapor deposition which has been in use since the 1950's (that patent has expired). but wasn't used to make carbon nanotubes till 1990's.

with the large number of suppliers i doubt if there are patents

organic,

it is totally made of carbon, of course is.

or inorganic.

metallic nanotubes have been produced, but then we are talking about carbon nanotubes, which have no metal.

at $150/gram, I'll take the can of flat black spray paint.

[Capt Slog]

I think they might be classified as another allotrope of carbon; there's diamond, graphite, and now this stuff.

I think it started out as buckyballs as mentioned.  The correct term for these is buckminster-fullerene and they are closed cages of 60 carbon atoms.  (Fuller is an architect who made dome structures out of hexagons and pentagons, which buckyballs resemble)

Nano tubes, are sort of buckyballs opened out and then continued to make a chain.  The artical quoted above talks about the light absorbing properties of them, but I believe that they are also supposed to be very strong.  They could be akin to a 'diamond rope', and they are the stuff that Arthur.C.Clarke had in mind when he wrote about the 'space elevator'.

[jacobs]

That's almost 5 times the price of gold! Flat black paint sounds even more attractive.

[MVIDSMITH]

georgia tech is doing now

p://www.azonano.com/news.asp?newsID=548

[bob golding]

from what i remember from my reading, buckyballs can be made with a arc welder and carbon electrodes. there is a professor who's name i cant recall at the moment, think he was /is at southampton university in the UK, who mentions this in one of his articles. apparantly before this method was discovered they were using expensive high tech vacuum chambers or something. bottom line is get a welder some carbon arc rods and a metal bucket and make your own buckyballs. not carbon nanotubes but would probaly do what you want to do ok.

cheers

bob golding

[finnsawyer]

Good explanation.  One explanation that I heard is that a carbon nano tube is like a one atom thick layer of graphite rolled over to make a tube.  Once you have a "seed" tube they will then grow just like any crystal keeping the straight tube structure.

[clarsondd]

Nanotubes were observed in 1991 in the carbon soot of graphite electrodes during an arc discharge, by using a current of 100 amps, that was intended to produce fullerenes. However the first macroscopic production of carbon nanotubes was made in 1992 by two researchers at NEC's Fundamental Research Laboratory. The method used was the same as in 1991. During this process, the carbon contained in the negative electrode sublimates because of the high temperatures caused by the discharge. The yield for this method is up to 30 percent by weight and it produces both single- and multi-walled nanotubes with lengths of up to 50 microns.

Because nanotubes were initially discovered using this technique, it has been the most widely used method of nanotube synthesis.  I believe the cost via this method is down to $50 ~ $100 per gram.

Determining the toxicity of carbon nanotubes has been one of the most pressing questions in Nanotechnology. Results from various scientific tests on cells have so far proven confusing, with some results indicating it to be highly toxic and others showing no signs of toxicity. This is primarily because of difficulties arising in spotting the nanotubes entering the cells from other carbon-based cell structures such as membranes. A recent research led by Alexandra Porter from the University of Cambridge shows once they are inside the cell, they accumulate in the cytoplasm and cause cell death.

[Clifford]

One always gets interesting comments.

Interesting comments by Georgia Tech.

They are wanting to market the nano technology to:

• Military
  
• Space Applications
  
  

I.E.  They want part of the Federal Government's cornucopia of money.

The one place nobody seems to talk about super high-efficiency solar cells would be the auto industry.

Certainly the applications/benefits of using in space would be that they could be used with no cover material, and should stay very CLEAN.