Photoinduced Radical Persistent Luminescence in Semialiphatic Polyimide System with Temperature and Humidity Resistance

Abstract

Organic persistent luminescence (pL) systems with photoresponsive dynamic features have valuable applications inthe fields of data encryption, anticounterfeiting, and bioimaging. Photoinduced radical luminescent materials have a unique luminous mechanism with the potential to achieve dynamic pL. It is extremely challenging to obtain radical pL under ambient conditions; on account of it, it is unstable in air. Herein, a new semialiphatic polyimide-based polymer (A0) is developed, which can achieve dynamic pL through reversible conversion of radical under photoexcitation. A "joint-donor-spacer-acceptor" molecular design strategy is applied to effectively modulate the intramolecular charge-transfer and charge-transfer complex interactions, resulting in effective protection of the radical generated under photoirradiation. Meanwhile, polyimide-based polymers of A1-A4 are obtained by doping different amine-containing fluorescent dyes to modulate the dynamic afterglow color from green to red via the triplet to singlet Förster resonance energy-transfer pathway. Notably, benefiting from the structural characteristics of the polyimide-based polymer, A0-A4 have excellent processability, thermal stability, and mechanical properties and can be applied directly in extreme environments such as high temperatures and humidity.

A photocatalytic redox cycle over a polyimide catalyst drives efficient solar-to-H2O2 conversion

“…There was no obvious signal at g = 2.003 in the dark. Upon light irradiation, the intensity of the signal at g = 2.003 significantly increased, indicating that photoinduced electrons were transferred to carbonyl groups, corresponding to imide radical formation 28 . These changes demonstrated that the reduction of R-C = O to the anion radical occurred on the PI-BD-TPB surface during the photocatalytic process.…”

Dual‐Stimuli‐Responsive Modulation Organic Afterglow Based on N─H Proton Migration Mechanism

“…Metal‐free organic afterglow emission, an appealing optical phenomenon that duration time over exceeding 0.1 s and can even be observed with the naked eye after following the cessation of excitation, [ 1 ] which has attracted great attentions due to its vast potentials in applications such as anticounterfeiting, [ 2 ] bioimaging, [ 3 ] information storage, [ 4 ] etc. However, mostly reported organic afterglow materials often occur in the crystalline state, which severely limits practical applications due to the necessary demanding condition for crystal growth.…”