Nonconjugated Hyperbranched Polyether Emitting Ultralong Room Temperature Phosphorescence with Tunable Emission and Afterglow

Abstract

Development of a nonconjugated room temperature phosphorescence (RTP) system with a lifetime longer than 1 s remains a challenge. Here, we report a nonconjugated RTP polymer composed of amide-terminated hyperbranched polyether cross-linked with boric acid, whose phosphorescence lifetime can reach up to 2.40 s with a maximum absolute quantum yield of 26.5%. Moreover, their phosphorescent emission wavelength can be tuned from 517 to 585 nm by changing the excitation wavelength from 300 to 480 nm, while the afterglow color can be regulated from blue to yellow-red. Particularly, the nonconjugated RTP polymer exhibits a dual stimulus response to humidity and temperature, so it is expected to find applications in anticounterfeiting. The present study provides a strategy to design an RTP system with tunable emission and prolonged afterglow.

Nonconjugated Organic Room-Temperature Phosphorescent Vitrimers with Multicolor Afterglow via Multicomponent Hybrid Copolymerization

“…Besides, the rigid BA cross-linked structures of PBEHA effectively reduced the nonradiative transition and stabilized the triplet states of phosphor, which also helped for phosphorescence emission. , In addition, the vacant p-orbital on B atoms could attack n transitions to generate a conjugate system and high characteristic 3 (π, π*) layout, leading to a long phosphorescence lifetime. This is because the 3 (π, π*) configuration can extremely slow down the decay rate due to the spin-flip-forbidden transition from 3 (π, π*) to 1 π 2 . ,, More importantly, reprocessed PBEHA showed no obvious change in the luminous properties after remolding (Figure S5), demonstrating the high efficiency and recyclability of the current reported RTP material. For PEHA, it only showed a short phosphorescence lifetime (27.97 ms) without afterglow due to the absence of BA cross-linked structures (Figures A, S6 and Table S2).…”

“…The structure of the PBEHA was first verified using Fourier transform infrared (FTIR) (Figures B and S1). The signals in the range of 3000–3600 and 1000–1170 cm –1 were due to the vibration absorption signals of −OH/–NH 2 groups and the stretching vibration signals of −C–O– bonds in PBEHA, respectively . The signals in the ranges of 980–1000, 860–920, and 770–840 cm –1 corresponded to in-plane B–N, B–O–C, and N–B–N bonds. ,,, These signals cannot be found for PEHA.…”

“…AM was incorporated into the copolymer system via the aze-Michael addition with HDA as well as the oxa-Michael addition reaction with the negative oxygen-ion formed by the ring opening reaction of EGDE . BA was incorporated due to the condensation reaction with amide/amino or hydroxyl groups. , By these reactions, cross-linked structures with dynamic covalent bonds including β-amino ester bonds and boron–ester bonds can be successfully synthesized, which enable the products (PBEHA) with good reprocessability. More importantly, the introduced BA cross-linked structures and the amide groups help to reduce the nonradiative attenuation from S 1 to S 0 and promote ISC of phosphors, which would realize RTP for PBEHA .…”

Full-Color-Tunable and pH-Responsive Ultralong Afterglow Based on a Single Polymeric Phosphor with Triple-Mode Delayed Emission

“…The photoluminescence spectra (Figure B) show bimodal models with λ max values at ∼425 and 600 nm regarding the film under UV (365 nm) irradiation. As the PMD concentration increases from 0.1 to 2 mg/mL, the fluorescence emission gradually increases in intensity, exhibiting the characteristic of aggregation-induced emission (AIE). , Then, it gradually decreases, displaying the characteristic of aggregation-caused quenching (ACQ) that can be explained by the inner-filter effect, corresponding to the enhanced absorption from 400 to 600 nm in the UV–vis spectra (Figures A and S10). More evidence is given by photoluminescence-excitation mappings (Figure S11), where the excitation of the red emission from 420 to 550 nm is divided into two parts at a high PMD concentration.…”

A flexible ligand and halogen engineering enable one phosphor-based full-color persistent luminescence in hybrid perovskitoids

“…20–25 Up to now, research on multi-color afterglow has achieved some success, and even obtained efficient and long-lived color-tunable RTP in rare materials. 26–31 For example, Huang et al reported a series of full-color RTP elastomers by modifying the chemical structure of monomers; 26 Tao et al achieved full-color RTP in polymer-based materials by doping a series of polycyclic aromatic hydrocarbons. 27 However, the full-color RTP in the reported materials is mostly derived from multiple chromophores, and one phosphor-based materials showing a recognizable afterglow are still limited.…”