Scientists have used wood’s natural ability to faintly glow to develop a new phosphorescent material. It has the potential to be used in a wide variety of applications, from medical imaging and optical sensing to dyes and inks that glow in the dark.
During the room-temperature phosphorescence (RTP) process, the material absorbs short wavelength energy (such as UV light) and then emits it as visible light. On the other hand, fluorescent materials stop glowing when the light is turned off.
An international team of researchers led by Northeastern Forestry University (China) and the University of Bath (UK) investigated the natural phosphorescent properties of lignin, the main component of wood. They found that, for example, linden is weakly phosphorescent in a natural way, emitting light within a few milliseconds due to the fact that lignin is in the three-dimensional matrix of cellulose. This inspired them to mimic the luminous properties of the material by cross-linking lignin into a three-dimensional polymer network.
As a result, it began to glow noticeably within about one second. Scientists have found that by changing the size of the cavities in the network and the drying time of the polymer, the duration of phosphorescence can be adjusted.
“Most modern phosphorescent materials are either toxic or difficult to prepare, so we wanted to develop a new one that overcomes these limitations,” says Professor Tony James of the Center for Sustainable Circular Technology at the University of Bath (UK).
To showcase the new material, the team used it to dye yarns that can be used in fluorescent textiles to protect against counterfeiting. In the future, it will be useful for medical imaging. Recall that medical imaging is a method and process of creating visual representations of the internal structures of the body for clinical analysis and medical intervention, as well as visual representation of the functions of certain organs or tissues.