Flexible and Self‐Healable Fluorescent Films with Tunable Emission via Solid‐Phase Molecular Self‐Assembly Design

Abstract Flexible luminescent materials are usually in the form of gels and films. Solid‐state films have advantages in practical applications due to their long‐term stability. However, the fabrication process by conventional methods remains laborious and unsustainable. Here, a facile and green route is reported for fabricating flexible luminescent films via an elegant solid‐phase molecular self‐assembly design. First, Eu ³⁺ /Tb ³⁺ ‐based metallosupramolecular coordination polyelectrolytes (MEPEs) and tetraphenylethylene (TPE)‐based MEPEs are designed with an antenna bis‐ligands to get individual R, G, and B emission. Then, by repeatedly pressing the MEPEs‐cetyltrimethylammonium bromide (CTAB) precipitates, obtained from their mixing aqueous solutions, R, G, and B emission films are obtained at room temperature, respectively. The emission color can be simply tuned by adjusting molar ratio of Eu ³⁺ : Tb ³⁺ : TPE. Notably, humidity‐responsive white emission film is obtained when Eu ³⁺ : Tb ³⁺ : TPE = 3:1:2.5. Owing to the dynamic coordination and electrostatic interaction, which can be activated by hydrating water, these films can be facilely reprocessed and self‐healed with the aid of water at room temperature. It is hoped that this approach to fabricate flexible supramolecular luminescent films can be applied to design various advanced functional soft materials.