Adjustable Room‐Temperature Phosphorescence through Tunable Aggregation of Dopants in Polymers and its Application in Hydrazine Hydrate Detection

Abstract The development of stimulus‐responsive phosphorescent materials has attracted increasing attention owing to their advantages in practical applications. However, those responses to toxic and hazardous chemicals remain rare owing to the lack of suitable design strategies. Herein, a new approach to regulate the room‐temperature phosphorescence (RTP) effect of doping systems is developed, in which two polar phenothiazine derivatives functionalized with trifluoroacetyl groups act as phosphorescent guests and polymer matrices with different polarities function as hosts. Regulated by the polymer host, the transition from aggregation to dispersion can be realized for guest molecules, resulting in enhanced RTP. Unlike traditional stimulus‐responsive materials, the doped system can undergo a dynamic state transition upon exposure to hydrazine hydrate vapor, thereby activating phosphorescence. Building on these findings, an effective model is established to investigate the effects of the transitions between aggregated and dispersed states. A novel stimulus‐responsive sensor is developed to detect hazardous hydrazine hydrates.