While we talk about going green, there is one particular thing that would be the prime candidate for recycling, and that would be the humble sheet of paper. However, have you ever wondered whether the day would arrive where a piece of paper can be used over and over again, without the need for using a pencil and an eraser? Chemists at the University of California, Riverside (UCR) has worked on a solution, having come up with what they proudly call the rewritable paper – as this is paper that can be printed on, not to mention erased – for over 20 times before it starts to lose its efficiency in this department.
The UCR prototype rewritable paper happens to be very different from the rest of the crowd, where it can be printed upon – only to be completely erased afterwards, before being reprinted if you so desire. This is made possible thanks to the special chemical properties of commercial inks that is known as redox dyes. Such dyes can be applied once, before a photomasked template is overlaid to let the combination be exposed to ultraviolet light, where the uncovered portions will then be photo-bleached away so that the print is left behind.
Reusing the sheet is simple – in order to erase the print, all one needs to do is to have it exposed to heat of around 115 °C (239 °F), and voila! You end up with a blank sheet. [Press Release]