Engineering Tunable Light Color in High-Performance\nRare Earth Fluorescent Polymers via Cation‑π Interactions

The\nunique fluorescent properties resulting from the distinctive\nelectronic structure of rare earth elements (RE) in polymer materials\nare well-documented, yet these materials often exhibit insufficient\nmechanical strength. Considering this challenge, two RE cation-π\ninteractions are introduced in this study to bestow exceptional mechanical\nproperties (the stress of indole-based epoxy resins has been enhanced\nfrom 60 to 90 MPa, accompanied by an increase in strain from 6% to\n11%) and excellent reprocessing and self-healing capabilities upon\nthe polymers through dynamic weak cross-linking. Additionally, through\ncapitalizing on the indole blue fluorescence of the substrate combined\nwith the red fluorescence of Eu<sup>3+</sup> and the green fluorescence\nof Tb<sup>3+</sup>, a wide color gamut of light-color tunability is\nachieved in the fluorescent polymer materials. The mechanical and\nfluorescent characteristics of RE-IERs are integrated, combining with\nthe computer programming system to introduce a strategy for multi-information\nencryption and anticounterfeiting applications.