Conducting Plastics..and more!!! Completely True!!!!

[Dream Master]

Hi all,

 

To get you started, here are what have been discovered:

- Conducting plastics

- electroluminescence of polymers (basically polymers/plastics which give off light when sandwiched between two electrodes with electricity flowing through them.

 

After searching a little on SFN to see whether the SFN community knows about conducting plastics and plastics which have electroproperties, I found up to near nothing about it (except the 11 posts made on it last year which people thought it was a fake idea [maybe arguable, but hey....]). Therefore I would like to share to you all a piece of great scientific knowledge to you all.

 

Last academic term during school, a lecturer from some university told us about the existence of conducting polymers. It all happened in the 70s when Hideki Shirakawa, a professor of chemistry athe university of tsukuba in Japan, was preparing the polymer polyacetylene when he accidently added 1000 times too much catalyst to the mixture. He curiously cound a shiny silver-coloured film formed on the wall of the reaction vessel. He found that this material conducted. This was absolutely new to him.

Meanwhile, Alan G. MacDiarmid and Alan J.Heeger had been working on a similar material in Pennsylvania. They talked about this material in a lecture during the attendence of Shirakawa. Because of this, Shirakawa got into contact with those two scientists and work began the further investigate the material. During one of their experiments, they found that when they exposed trans-polyacetylene to bromine vapour, the conductivity of the substance increased by a factor of 10 million. The discovery was so great that these three published their work. In 2000, the three scientests were awared the ultimate scientific honour, the Nobel prize in chemistry "for the discovery and development of electrically conductive polymers".

 

The publication of this aroused the interest of the entire scientific community. Some time later, University of Cambridge developed a polymer which gave off light when sandwiched between two electrodes with electricity flowing thorugh them. This gave rise a whole new varieties of inventions - Pure Plastic LEDs. Traditionally, LEDs were made of complex crystalline structures, only about 25% efficient. Now, these plastic LEDs can do the same job but with 45% efficiency!! Of course, thats only a taster. Some time later again, they formed an idea of creating a massive structure of polymers to form a complete an image - plastic screens. These would be lightweight, compact, durable, efficient and FLEXIBLE. Since then, Cambridge formed a company called Plastic Logic which have so far managed to make 10 inch big plastic FLEXIBLE displays, which can do basically what a computer monitors does - change images etc....

(There are images / videos on the http://www.plasticlogic.com/hi-res.php which shows some real workings of these displays)

 

Of couse, there are also other ideas....automatic darkening windows that tint when the sun shines too brightly, or for privacy. Basically a computer attached to a light sensor detects light and allows electricity to be "given" to the window. The more electricity - the darker it gets. This is already out in the market. Another invention - solar panels. Certain polmers can be used to convert photons into electricity.

There are loads more inventions with these polymers....I can be bothered to type the details of them all up so here is a small list of them.

- rechargeable polymer batteries

- light, thin layer of conductive polymer used to absorb electromagnetic rays - have a high resistance to temperature. Used for outer coating of rockets.

- Ultra thin teles/screens - used for military, e.g. used as map (download image via satellite).

- used in stealth planes - a polymer coating on the outside of the plane which basically "conducts" electromagnetic rays from radars from the front of the plane to the back. Basically making the stealth plane "see-through"

- Along the same line - as there are polymer screens, they can be used on stealth planes, whereby computers sense the color of the sky and changes to color of the polymer to the color of the sky, effectively making the plane "invisible".

 

If you don't believe me, search on the net. "Conducting polymer"

 

Have fun digesting!!!

DM

P.S if you want more about special polymer properties, ask

[akcapr]

wow thats really cool very futuristic

[5614]

The colour changing (aka electrochromic) glass you refer to can work very well without the need of conducting polymers. They can be designed with liquid crystals and in another ways (e.g. using suspended particles which can block light). See here for info:

http://electronics.howstuffworks.com/smart-window.htm

 

Also conducting polymers is quite old news... although they are obviously still under development. Here is an IBM reasearch paper written in August 2000:

http://www.research.ibm.com/journal/rd/451/angelopoulos.pdf

The paper "reviews some of these applications and briefly describes possible future applications of conducting polymers".

[Dream Master]

Of course...smart windows can work without conducting polymers, but SPDs have several disadvantages:

- probably more expensive

- it's kinda a liquid, so requires more treatment (i.e. squidging it between two planes of glass or plastic

 

Anyway....Electrochromic glass is basically made from conductive polymer Polyaniline.

 

Also, the big thing about these plastic displays is the fact that they will be comming out very soon. As the 10-inch plastic display was just introduced last year in Dec.

http://www.digitimes.com/displays/a20051206PR201.html