Despite claims that plain paper will soon cease to be used as a carrier of information, people still use it in large quantities. For example, to write notes that are not stored for a long time. That is why now several scientific teams are developing the so-called rewritable or reusable paper. According to the developers, this paper will help to save tons of sheets. About the latest development in the journal ACS Applied Materials and Interfaces, said Chinese scientists.
Specialists of the Fujian pedagogical University as a basis took a sheet of the most common paper for printing and covered one of its sides with thermochromic blue paint, which becomes colorless when heated. The other side is covered with photothermal black toner, which conducts heat and releases heat under the influence of light. They then drew patterns on the blue side of the sheet with a heat-emitting pen. The toner is heated and discolor the paint in place of the lines being drawn, revealing a white paper.
The developers note that unlike previous experiments, this paper is easy to make, and to erase the record, you do not need to use ultraviolet radiation. It is enough just to cool it to -10 degrees Celsius and it is” reset ” for new use. This procedure can be repeated at least 100 times without loss of quality.
It is possible to write on such paper not only with the heat pen, but also with the light of the near infrared range, and also to print by means of the thermal printer. Typically, reusable paper fades in a few days or weeks. Chinese invention saves text and images up to six months at room temperature