Print, wipe, rewrite
Despite the ubiquity of tablet computers and e-readers, we simply cannot erase our addiction to paper. An estimated four billion trees are felled every year to make paper or cardboard, an energy-intensive process with a vast environmental footprint. Now chemist Yadong Yin of the University of California, Riverside, and his colleagues have developed “rewritable” paper that could help curb that impact.
The researchers coated conventional paper with nanoparticles of two chemicals: Prussian blue, the pigment that gives blueprints their characteristic color, and titanium dioxide, a substance used in sunscreens. A blast of ultraviolet light makes the titanium dioxide nanoparticles donate electrons to their Prussian blue neighbors. That jolts the pigment into shifting its color from midnight blue to milky white.
By shining that UV light through a transparent screen marked with black text, the researchers “printed” blue text on a white background. The text lasts about five days and then spontaneously fades away: “Every morning I could just push a button, and a printer would give me a fresh newspaper to read over breakfast,” Yin says.
The paper can also be reset by heating and reused more than 80 times, a significant improvement over previous types of rewritable paper. “The key advantages are high reversibility and stability, easy handling, low cost and low toxicity,” says Sean X. Zhang, a materials scientist at Jilin University in China, who was not involved in the study but has also worked on developing rewritable paper. By comparison, technologies such as electronic ink—used for Amazon's Kindle Paperwhite—involve moving charged black-and-white particles around, which requires electronics.
Source & further reading:
https://www.scientificamerican.com/article/reprintable-paper-offers-sustainable-alternative-to-the-printed-word
Image: Printed rewritable paper made using Prussian blue nanoparticles.
Credit: Courtesy of Yadong Yin University of California, Riverside
#science #nanoworld #nanoparticles #research
I still hand write my daily work log into a paper military log book. It gives a little bit of "me" into a written medium that is not so easily done electronically..........some of me is old fashioned.......guess it's why I am big on recycling all the paper I have to shred....
ReplyDeleteThere is something about pen and paper that will always have appeal, quick, cheap, no electricity and easy to note and doodle. Sometimes old technology can be the best technology.
ReplyDeleteWhat we can improve on is use of recycled paper, or other sources, that you perhaps could grow yourself, or a by product of 'greening' cities. That is still more expensive than the raw source. I think it is only when we run out of trees or if regulation / taxes are implemented on using unsustainable/unethical sources will that change.
Oh noes. No need for chemistry or inventions that waste so many resources. :(
ReplyDeleteI prefer any wall with blackboard paint plus a piece of chalk over such unnecessary inventions within the category let's find a way to profit from this phenomenon.
Real innovation should never be about optimization of old habits by wasting more energy. 80 times reusability means nothing to me, unless I can compare the energy waste of the products life cyle.
I still keep some of my first class school writings, I'd never like to see them fading away. They are written on paper. With ink. But I can show it to my kids and later on to my grandkids.
Like to really spare resources? Print less. Copy less. Write down necessary stuff, only. Use switchable power-strips. Talk to others in person. And stop using the internet as an infinite magical treasure box. Each second online, each bit transferred = your personal raise in energy fingerprint. You destroy more trees by being online than writing down stuff on paper. Try to use this planet more wisely.