Visible‐Light‐Driven Photoswitchable Fluorescent Polymers for Photorewritable Pattern, Anti‐Counterfeiting, and Information Encryption

Abstract Photoswitchable fluorescent polymers (PFPs) are emerging as a class of promising systems for photowritable pattern, optical anti‐counterfeiting, and information encryption. They typically use harmful UV light as the stimulus, which often leads to inevitable photobleaching and poor reversibility. To address this issue, visible‐light‐driven PFPs by copolymerization of novel negative photochromic spiropyran monomer and methyl acrylate are developed. The obtained copolymers display bright red fluorescence, which can be reversibly turned off by visible light irradiation. Many appealing features are observed in this system, including fast photo‐responsibility, prominent photo‐reversibility and photostability, simple preparation process, and processability. Their applications in photorewritable patterns, optical anti‐counterfeiting, and information encryption are also demonstrated.