Chemically tunable lanthanide metallogel emits different colors depending on conditions.
A group of researchers at MIT have developed a family of metallic polymer gels made with rare earth elements that are capable of emitting controllable colored light.
The metallogel is made from lanthanide metals combined with a polyethylene glycol (PEG) polymer. The gel can be chemically tuned to emit different colored light over a wide spectrum, including white light. The light emissions are in response to chemical, biological, mechanical or thermal stimuli affecting a material compound or physical structure.
“It’s super-sensitive to external parameters,” said Niels Holten-Andersen, assistant professor at MIT. “Whatever you do will change the bond dynamics, which will change the color.”
The material can be made into a gel, a thin film, or a coating that could be applied to structures. Because it can detect stresses in mechanical systems, explained Holten-Andersen, it can potentially indicate the development of a failure before it actually happens.
It is also difficult to measure forces in fluids, Holten-Andersen said, but an approach using this metallogel could provide a sensitive means of doing so.
The metallogel can also be engineered to detect specific pollutants, toxins or pathogens and provide visible results through color-coded emissions.
MIT’s material is an example of work with biologically inspired materials, Holten-Andersen explained. “My niche is biomimetics – using nature’s tricks to design bio-inspired polymers,” he said. “We’ve barely scratched the surface of trying to understand how they’re put together, from a chemical and mechanical standpoint.”
The idea is not to copy nature, he emphasized, but to understand and apply the underlying principles of natural materials.
A paper by Holten-Anderson and his colleagues describing the metallic polymer was published in the Journal of the American Chemical Society and is available here.