Engineering Tunable Light Color in High-Performance Rare Earth Fluorescent Polymers via Cation-π Interactions

The unique fluorescent properties resulting from the distinctive electronic structure of rare earth elements (RE) in polymer materials are well-documented, yet these materials often exhibit insufficient mechanical strength. Considering this challenge, two RE cation-π interactions are introduced in this study to bestow exceptional mechanical properties (the stress of indole-based epoxy resins has been enhanced from 60 to 90 MPa, accompanied by an increase in strain from 6% to 11%) and excellent reprocessing and self-healing capabilities upon the polymers through dynamic weak cross-linking. Additionally, through capitalizing on the indole blue fluorescence of the substrate combined with the red fluorescence of Eu3+ and the green fluorescence of Tb3+, a wide color gamut of light-color tunability is achieved in the fluorescent polymer materials. The mechanical and fluorescent characteristics of RE-IERs are integrated, combining with the computer programming system to introduce a strategy for multi-information encryption and anticounterfeiting applications.