Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Chemists fabricate novel rewritable paper
by Staff Writers
Riverside CA (SPX) Dec 03, 2014


Yadong Yin's lab at the University of California, Riverside has fabricated novel rewritable paper, one that is based on the color switching property of commercial chemicals called redox dyes. Image courtesy Yin Lab, UC Riverside.

First developed in China in about the year A.D. 150, paper has many uses, the most common being for writing and printing upon. Indeed, the development and spread of civilization owes much to paper's use as writing material.

According to some surveys, 90 percent of all information in businesses today is retained on paper, even though the bulk of this printed paper is discarded after just one-time use.

Such waste of paper (and ink cartridges)--not to mention the accompanying environmental problems such as deforestation and chemical pollution to air, water and land--could be curtailed if the paper were "rewritable," that is, capable of being written on and erased multiple times.

Chemists at the University of California, Riverside have now fabricated in the lab just such novel rewritable paper, one that is based on the color switching property of commercial chemicals called redox dyes.

The dye forms the imaging layer of the paper. Printing is achieved by using ultraviolet light to photobleach the dye, except the portions that constitute the text on the paper. The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.

"This rewritable paper does not require additional inks for printing, making it both economically and environmentally viable," said Yadong Yin, a professor of chemistry, whose lab led the research. "It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation."

Study results appear online in Nature Communications.

The rewritable paper is essentially rewritable media in the form of glass or plastic film to which letters and patterns can be repeatedly printed, retained for days, and then erased by simple heating.

The paper comes in three primary colors: blue, red and green, produced by using the commercial redox dyes methylene blue, neutral red and acid green, respectively. Included in the dye are titania nanocrystals (these serve as catalysts) and the thickening agent hydrogen cellulose (HEC). The combination of the dye, catalysts and HEC lends high reversibility and repeatability to the film.

During the writing phase, ultraviolet light reduces the dye to its colorless state. During the erasing phase, re-oxidation of the reduced dye recovers the original color; that is, the imaging material recovers its original color by reacting with ambient oxygen. Heating at 115 C can speed up the reaction so that the erasing process is often completed in less than 10 minutes.

"The printed letters remain legible with high resolution at ambient conditions for more than three days - long enough for practical applications such as reading newspapers," Yin said.

"Better still, our rewritable paper is simple to make, has low production cost, low toxicity and low energy consumption."

His lab is currently working on a paper version of the rewritable paper.

"Even for this kind of paper, heating to 115 C poses no problem," Yin said. "In conventional laser printers, paper is already heated to 200 C in order to get toner particles to bond to the paper surface."

His lab also is working on increasing the cycling number (the number of times the rewritable paper can be printed and erased), with a target of 100, to reduce overall cost. His research team is exploring ways to extend the legibility of the printed texts or images for more than three days to expand their potential uses.

"One way is to develop new photocatalyst nanoparticles that become highly reductive when irradiated by ultraviolet light," Yin said.

"We are exploring, too, the possibility of multi-color printing. The design principle can be extended to various commercial redox dyes to produce rewritable paper capable of showing prints of different colors. All these efforts will help increase the practical applications of the technology."

He was joined in the study by UC Riverside's Wenshou Wang (first author of the research paper), Ning Xie and Le He. Wang and Yin conceived and designed the experiments. Wang performed the experiments. Xie and He contributed to sample analysis. Wang and Yin analyzed the results.

The research was funded by a grant to Yin from the U.S. Department of Energy.

This technology has been disclosed and assigned UC case number 2015-250. A provisional patent has been filed and the UCR Office of Technology Commercialization is actively seeking a company to license the technology.

Yin's lab has recently synthesized a colloidal titania nanoparticle catalyst doped with barium ions that enables reversible light-responsive color switching with excellent cycling performance and considerably high switching rate.

"The improved performance is attributed to the more effective removal of the photogenerated oxidative holes that results from barium doping. This leaves more electrons for promoting the reduction of redox dyes," Yin said.

The finding was recently reported in Angewandte Chemie.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of California - Riverside
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Penn Research Shows Way to Design 'Digital' Metamaterials
University Park PA (SPX) Dec 03, 2014
Metamaterials, precisely designed composite materials that have properties not found in natural ones, could be used to make light-bending invisibility cloaks, flat lenses and other otherwise impossible devices. Figuring out the necessary composition and internal structure to create these unusual effects is a challenge but new research from the University of Pennsylvania presents a way of s ... read more


TECH SPACE
Carnegie Mellon Unveils Lunar Rover "Andy"

Why we should mine the moon

Young Volcanoes on the Moon

Russia Preparing Joint Moon Exploration Agreement With EU

TECH SPACE
Red Planet's Mystery

Meteorite From Mars Contains Alien Biomass

Traces of possible Martian biological activity inside a meteorite

Meteorite stirs life-on-Mars debate

TECH SPACE
Orion flight marks 'milestone' for US space program: NASA

Orion launch is trial by fire for Apollo-era heat shield

NASA's Orion pushes boundaries of human spaceflight

Pop culture artifacts aboard Orion spacecraft

TECH SPACE
Service module of China's returned lunar orbiter reaches L2 point

China Launches Second Disaster Relief Satellite

China expects to introduce space law around 2020

China launches new remote sensing satellite

TECH SPACE
ISS Enables Interplanetary Space Exploration

NASA's CATS Eyes Clouds, Smoke and Dust from the Space Station

3-D Printer Creates First Object in Space on ISS

Soyuz docks at Space Station; Expedition 42 joins crew

TECH SPACE
Japan launches rocket carrying asteroid probe

Go-ahead given for Ariane 5 dual-payload mission

Ariane 5 delivers DIRECTV-14 and GSAT-16 to orbit

Launch of European Ariane-5 Space Rocket From Kourou Postponed

TECH SPACE
'Mirage Earth' exoplanets may have burned away chances for life

Stardust Not Likely to Block Planet Portraits

Finding infant earths and potential life just got easier

Ground-based detection of exoplanets

TECH SPACE
Chemists fabricate novel rewritable paper

Space travel is a bit safer than expected

Penn Research Shows Way to Design 'Digital' Metamaterials

MatSE researchers develop inexpensive hydrolyzable polymer




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.