Chemists at the University of California, Riverside have now fabricated rewritable paper in the lab, 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.”
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 hydroxyethyl cellulose (HEC). The combination of the dye, catalysts and HEC lends high reversibility and repeatability to the film.
Research like this is an example of Seizing Our Destiny’s catalyst for innovation pillar. The students and staff at UC Riverside cultivate and support ideas, research, and products that accelerate the common good for all. Creativity and innovation permeate all that we do in Riveside, which makes our community a trendsetter for the region, state, and the world to follow.
Study results appear online in Nature Communications.
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