Fluorescence and self-healing property of the flower-printed film of terpolymer composed of ethylene, anisylpropylene, and pyrenylethenyl-substituted styrene. Credit: RIKEN
A research team at the RIKEN Center for Sustainable Resource Science (CSRS) has succeeded in developing a self-healing material that is also capable of emitting a high amount of fluorescence when absorbing light.
Five years ago, researchers successfully co-polymerized ethylene and anisylpropylene using a rare-earth metal catalyst. The resulting binary copolymer displayed self-healing properties against damage. Now, intending to build upon their initial success, the team incorporated a luminescent unit—styrylpyrene—into a monomer, and then formed polymers that included anisylpropylene and ethylene.
The resulting copolymer not only proved to be tough, but also exhibited self-healing without external stimuli or energy. Its tensile strength fully recovered within 24 hours, demonstrating a high self-healing speed compared with binary copolymers. The material was able to self-heal in water, acidic and alkaline solutions, giving it potential uses in a variety of environments.
The material also showed an added property. The research team was able to successfully transfer a 2D image onto the fluorescent self-healing film through photolithography. Although the image remained invisible under natural light, it became recognizable under ultraviolet light—suggesting potential applications for the film as an information storage device. The film maintained its excellent self-healing and elastomeric properties even with the images.
“The material we synthesized, through a one-step reaction, gave us the ability to control its optical and mechanical properties by adjusting the composition of the monomer. We think it could contribute significantly to the development of novel functional materials with high self-healing capabilities in various practical environments,” said study author Zhaomin Hou.