Highly tunable ultralong room-temperature phosphorescence from ionic supramolecular adhesives for multifunctional applications

Abstract Molecular room-temperature phosphorescent (RTP) materials with ultralong-lived excited states have attracted extensive attention in both academia and industry. However, the soft and flexible RTP materials with facile processability are still very limited. In this work, we report the first example of supramolecular adhesives (SAs) with tunable ultralong RTP lifetime as high as 638.9 ms, based on the self-assembly of low-molecular-weight sodium m-carboxyphenylborate and solvent molecules. Interestingly, the fabricated SAs show strong adhesion performance to various substrates, especially for glass and tile. Both experimental and theoretical studies indicate that multiple intermolecular interactions (such as hydrogen-bonding, π-π interaction, and electrostatic force) efficiently promote the formation of cross-linked network structure, which helps to construct a rigid microenvironment to boost the RTP emission. Moreover, multifunctional applications including product labeling, positioning adhesion, encryption, and decoration are well-demonstrated by integrating the strong adhesion and long-afterglow properties. Therefore, this work provides an effective strategy to design and synthesize novel SAs with ultralong RTP by combining low-molecular-weight phosphors and readily available solvents, which have great practical application prospects in information safety and anti-counterfeiting fields.