Achieving Stimuli-Responsive Amorphous Organic Afterglow in Single-Component Copolymer through Self-Doping

Abstract

The development of stimuli-responsive materials with afterglow emission is highly desirable but remains a formidable challenge in a single-component material system. Herein, we propose a strategy to achieve photoactivated afterglow emission in a variety of amorphous copolymers through self-doping, endowed by the synergetic effect of self-host-induced guest sensitization and thermal-processed polymer rigidification for boosting the generation and stabilization of triplet excitons. Upon continuous ultraviolet illumination for regulating the oxygen concentration, a photoactivated afterglow showing increased lifetimes from 0.34 to 867.4 ms is realized. These afterglow emissions can be naturally or quickly deactivated to the pristine state under ambient conditions or heating treatment. Interestingly, programmable and reusable afterglow patterns, conceptual pulse-width indicators, and “excitation-time lock” Morse code are successfully established using stimuli-responsive afterglow polymers as recorded media. These findings offer an avenue to construct a single-component polymeric system with photoactivated organic afterglow features and demonstrate the superiority of stimuli-responsive materials for remarkable applications.

Light‐Induced Electron Transfer Toward On/Off Room Temperature Phosphorescence in Two Photochromic Coordination Polymers

“…Four Zn 2+ S2, Supporting Information). HEDP anions connect Zn 2+ ions with two different coordination modes of μ 4 -𝜂 1 :𝜂 1 :𝜂 0 :𝜂 0 :𝜂 1 :𝜂 1 :𝜂 1 and μ 5 -𝜂 1 :𝜂 1 :𝜂 2 :𝜂 1 :𝜂 1 :𝜂 1 :𝜂 1 . The HEDP anions chelate/bridge with Zn 2+ ions to form a 2D layer (Figure S1a, Supporting Information).…”

Achieving White‐Light Emission Using Organic Persistent Room Temperature Phosphorescence

“…Higher triplet states quickly decay to T 1 via internal conversion (IC) according to Kasha's rule, and radiative decay from a triplet excited state to the ground state results in phosphorescence. [31] A molecule in the T 1 excited state can also jump to S 1 by reverse intersystem crossing (RISC), leading to delayed fluorescence. [32] The phosphorescence from purely organic materials is often measured at low temperatures in a N 2 or Ar 2 atmosphere, as nonradiative relaxation pathways such as quenching by oxygen or moisture (k q ), and vibrational relaxation (k nr ) have a large influence on the efficiency of phosphorescence.…”

A Dual‐Responsive Liquid Crystal Elastomer for Multi‐Level Encryption and Transient Information Display

“…With the booming of the Internet of Things (IoT) and 5G wireless communications technology, information security becomes more and more important, promoting the development of responsive materials and technologies for encryption, anti-counterfeiting, and secure storage of information. In recent years, tremendous efforts have been made to develop advanced anti-counterfeiting materials and corresponding encryption techniques, including photonic crystals, [1][2][3][4][5] structural-color materials, [6][7][8] rewritable materials, [9][10][11] wrinkles, [12][13][14] watermarks, [15] holograms, [16] and fluorescent/phosphorescent imaging, [17][18][19][20] etc, to avoid the threat of false information and information leakage. By combining multiple anti-counterfeiting techniques or multiple stimuli (such as light, temperature, pH, and moisture) that trigger decryption, the information is thus made more difficult to copy, enhancing the security level.…”