With the environmental issues surrounding paper and paper-based waste coming to the forefront of concerns once again, researchers carrying out a brand new study on the reactions of paper’s reaction to light and other sources have begun the development of a rewritable paper using UV light. The astonishing breakthrough on the possibilities of rewritable paper was published recently in a paper written by researchers Wenshou Wang and co-authors based at Shandong University in China, The University Of California, Riverside and the Lawrence Berkeley National Laboratory in America.
How does rewritable paper work?
The theory behind being able to directly print onto paper using a light source comes from the colour-changing properties of nanoparticles, which during the research, were applied to a number of conventional paper sheets. Once this coating was applied, UV light was then shone onto the paper which in turn, transformed the paper into a rewritable version. To erase the print on the paper, the paper would need to be heated to 120°C and could be re-written on for more than 80 times approximately before the paper would return to its normalised state.
How will this help environmental issues?
Paper as a material and paper production in general has a substantial negative impact on the environment and has only worsened as time has moved on. The production of paper is actually a leading source of industrial pollution and waste paper (when incorrectly discarded) accounts for approximately 40% of all landfills around the world. Along with this there are the ever present worries surrounding deforestation in order to produce more paper and paper based materials.
Whilst scientists and researchers have investigated into the possibility of creating disposable paper, it has often been criticised for not being cost effective and still contributing to the environmental issues that regular paper creates. With the new discovery of rewritable paper, it has created far more possibilities and is an important step in attempting to solve this problem. A resolution this could provide is with the production of short-term use printed materials (such as leaflets, flyers and other temporary documents). Using these nanoparticle inks, printed materials can then be completely erased and reused for other purposes once the information on them has been absorbed. This could work especially well on high volume reading materials such as newspapers, magazines, notepads and posters.
What happens next?
With the exciting potential impact that light-printable paper could have on the print industry as whole, research is said to be continuing on this new revelation to further fine tune and understand more of the principles behind the scientific properties it contains. Future plans are to bring this technology to a much more practical use, with Yadong Yin, Chemistry Professor at the University of California stating that the “immediate next step is to construct a laser printer to work with this rewritable paper to enable fast printing” and that they “will also look into effective methods for realizing full-colour printing”.
Phys.org- No ink required: paper can be printed with light: https://phys.org/news/2017-02-ink-required-paper.html
Journal – Nano Letters: http://pubs.acs.org/journal/nalefd