Photo‐Induced Dynamic Room Temperature Phosphorescence Based on Triphenyl Phosphonium Containing Polymers

Abstract

Long‐lived room temperature phosphorescence (RTP) systems have become a research focus in the field of functional materials due to their fascinating luminescence properties. However, it is still an enormous challenge to realize RTP under ambient conditions, since RTP can be quenched easily by molecular oxygen. Herein, two polymer acceptors containing triphenyl phosphonium bromide salt are designed and synthesized successfully. They are then doped into a poly(methyl methacrylate) matrix with donor molecules to form flexible films with long‐lived RTP. Interestingly, the long‐lived RTP performance is highly dependent on the grafting rate of the polymers. Upon increasing the grafting rate, the aggregation degree of polymer acceptors increases, further inhibiting the molecular movement in the aggregates and reducing nonradiative vibration deactivation of triplet excitons for achieving green long‐lived RTP. Meanwhile, the visualization of real information and complete pattern after 365 nm UV irradiation is demonstrated based on these long‐lived RTP systems, presenting application potential toward dynamic multilevel information encryption and display devices. This work provides an innovative principle for the activation of long‐lived RTP in the polymeric systems under ambient conditions.

Poly(arylene piperidine) Quaternary Ammonium Salts Promoting Stable Long‐Lived Room‐Temperature Phosphorescence in Aqueous Environment

“…Compared to numerous previously reported RTP of quaternary ammonium systems, the phosphor-doped PMMA matrix, RTP in water, and PBHDB@ PMMA film in air or soaked in water exhibits a longer phosphorescence lifetime (Figure 1c). [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] Interestingly, the PBHDB@PMMA film still exhibited extraordinary turquoise phosphorescent emission with a duration of 10 s, as observed by naked eyes in water (Video S1, Supporting Information). As depicted in Figure S15, Supporting Information, the UV absorption intensity of the film slightly decreased after soaking it in water.…”

“…In addition, a stable turquoise afterglow emission was achieved in water, which is rarely observed in Images of three doped polymer matrix films (HDBP@PMMA, PBN@PMMA, and PBHDB@PMMA) after 254 nm UV irradiation for 30 s. b) Proposed mechanism of long-lived polymeric RTP. c) Comparison of phosphorescence lifetime between film PBHDB@PMMA and existing research [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] on quaternary ammonium salt systems, phosphors-doped PMMA matrix systems, and RTP in water. organic polymeric systems, especially for those without complex cross-linking structures.…”

Photoprogrammable Circularly Polarized Phosphorescence Switching of Chiral Helical Polyacetylene Thin Films

“…The phosphor BrNpA in the ground state (S 0 ) absorbed the photons was excited to S 1 state under UV irradiation, and then to the T 1 through ISC transition. However, the highly reactive nonradiative energy transfer from the triplet state of the phosphor to triplet oxygen could lead to the quenching of phosphorescence [33][34][35][36] . After a sustaining UV irradiation over a period of time to consume the dissolved oxygen in PMMA film, then the triplet excitons could decay as phosphorescence rather than being quenched by oxygen molecules, thus producing the photoinduced RTP characteristic (Figure 4c).…”

Long-Lived Organic Room-Temperature Phosphorescence from Amorphous Polymer Systems

“…In comparison to metal-free RTP small molecules that rely on crystal engineering with limited processability and flexibility, amorphous polymer-based organic RTP materials have some attractive aspects with respect to practical applications. , Numerous interactions such as hydrogen bonding, ionic bonding, and covalent bonding in amorphous polymer systems can effectively impede molecular motion and promote the ISC process, leading to highly efficient RTP emission . Moreover, these inter/intramolecular interactions and long-lived triplet excitons are more sensitive to external perturbations such as light, temperature, and humidity, which provide the possibility to construct intelligent stimulus-responsive RTP polymers. − With diverse environmental stimuli, the intelligent RTP polymers are capable of changing the corresponding RTP behavior such as the emission color, lifetime, or intensity. Their long-lived RTP emissions can be directly captured by the naked eye for in situ real-time visualization, offering unique advantages over conventional stimulus-responsive fluorescence materials.…”