Organic afterglow coating materials via emulsion polymerization

Abstract

Organic room-temperature phosphorescent (RTP) materials are of increasing interest due to their unique triplet-state emission and potential applications in anti-counterfeiting, bioimaging, and optical storage. However, challenges such as low emission efficiency, short lifetimes, and limited scalability have hindered their practical use. Herein, we report a facile and scalable synthesis of difluoroboron β-diketonate (BF₂bdk) compounds and their incorporation into a poly(methyl methacrylate) (PMMA) matrix via emulsion polymerization. The rigid microenvironment of PMMA effectively suppresses non-radiative decay of the triplet state, yielding an RTP emulsion with a phosphorescence lifetime of up to 1.38 s. Blending with commercial emulsions enables the fabrication of uniform, transparent RTP coatings that can be obtained with bright afterglow exceeding 10 s. These coatings exhibit excellent environmental stability, thermal and chemical resistance, and industrial applicability. This study addresses the long-standing challenge of the scalable fabrication of aqueous afterglow materials, and offers a promising route for the large-scale production of high-performance organic RTP materials, paving the way for their integration into diverse application scenarios such as advanced optical and security technologies.