Rewritable paper can use 20 times to write.

Paper....!!!!! Every person from morning to evening using this. Children used this paper to play a games, making of paper boats, etc... Adults use this paper for writing, drawing, printing etc... Entrepreneurs or business man uses for printing their business articles etc... And so on.. And foreigners using this as tissue also. What else....???? Every where we are using this paper.

And in some poor countries, beggers collect papers by wondering on the roads and they sold in some shops to feed them that day.

History of paper :

First developed in China in A.D 150. 90% of all information in business is retained on paper, which is recent studies saying.

Advantages :

• Writing
• Printing
• Making of paper toys
• Painting etc.....

Disadvantages :

To made this paper we have to do so many things like....

• Deforestation
• Chemical pollution to air
• Dumping problems

So, as these disadvantages may be a problem for human race. So, in order to avoid these problems, university of California invented a new thing I.e, rewritable paper. Let's see...

Rewritable paper ( California university ) :

Chemists at university of California, Riverside have now fabricated in the lab just such a rewritable paper, one that is based on the color switching property of commercial chemicals called " redox dyes ". This dye forms the imaging layer on paper.

Printing is achieved by using UV light to photobleach the dye, except the portions that constitute the test on paper.

We can write and erase the erase the paper 20 times. " The rewritable paper doesn't require additional links for printing making it both economically and environmentally viable ", said yodong yin, professor of chemistry.

The rewritable paper is essentially rewritable media in the form of glass or plastic to which letters can be repeatedly printed. And erased by simple heating.

In which colours :

Paper comes in 3 colours. They're blue, red, green produced by using redox dyes methylene blue, neutral red and acid green.

These 3 colours are universal colours. We can see the combined colours gives different colours.

• Red + Green   =  yellow
• Green + Blue  =  cyan 
• Blue Red         =  magenta

Yellow, cyan and magenta are secondary colours. Red, green and blue are primary colours. By the presence of " holes " in our retina, we can able to see the colours. The more in holes can be more visible to colours.

By heating :

By heating at 115°C can speed up the reaction so that the erasing process can often completed in less than 10 minutes.

It's not a problem by heating at 115°C because, in conventional laser printers, paper is already heated to 200°C in order to get tonner particles to bond to paper surface.

Advantages of rewritable paper :

• Simple to make
• Low production cost
• Low toxicity
• Low energy consumption

Goal :

As this paper can now rewritable 20 times. Their goal is for rewritable 100 times to reduce the cost.

Funds :

The research was funded by a grant to Yin from USA department of energy.

Add any more story....???? Or any ideas, please comment below.....