Mechanochromic Fluorescent Polymers Enabled by AIE Processes

• Published in: Macromolecular rapid communications. Vol. 42; no. 1; pp. e2000311 - n/a
• Main Authors: Han, Ting, Liu, Lijie, Wang, Dong, Yang, Jinglei, Tang, Ben Zhong
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2021
• Subjects: aggregation‐induced emission; Conformation; Emission; Emissions; Fluorescence; Fluorescent Dyes; Humans; Mechanical stimuli; mechanochromic polymers; Mechanoluminescence; Molecular conformation; Polymers; Smart materials; Stimuli; aggregation-induced emission; fluorescence; mechanochromic polymers
• ISSN: 1022-1336; 1521-3927; 1521-3927
• DOI: 10.1002/marc.202000311

Polymeric materials are susceptible to the chain re‐conformation, reorientation, slippage, and bond cleavage upon mechanical stimuli, which are likely to further grow into macro‐damages and eventually lead to the compromise or loss of materials performance. Therefore, it is of great academic importance and practical significance to sensitively detect the local mechanical states in polymers and monitor the dynamic variations in polymer structures and properties under external forces. Mechanochromic fluorescent polymers (MFP) are a class of smart materials by utilizing sensitive fluorescent motifs to detect polymer chain events upon mechanical stimuli. Taking advantage of the unique aggregation‐induced emission (AIE) effect, a variety of MFP systems that can self‐report their mechanical states and mechano‐induced structural and property changes through fluorescence signals have been developed. In this feature article, an overview of the recent progress on MFP systems enabled by AIE process is presented. The main design principles, including physically doping dispersed or microencapsulated AIE luminogens (AIEgens) into polymer matrix, chemically linking AIEgens in polymer backbones, and utilizing the clusterization‐triggered emission of polymers containing nonconventional luminogens, are discussed with representative examples. Perspectives on the existing challenges and problems in this field are also discussed to guide future development. Mechanochromic fluorescent polymers (MFPs) can change their fluorescence properties with local polymer deformation responses under mechanical forces. The unique aggregation‐induced emission (AIE) processes enable the development of diverse MFPs. The main design principles include physically doping dispersed or microencapsulated AIE luminogens (AIEgens) into polymer matrix, chemically bonding AIEgens in polymer backbones, and the rational utilization of clusteroluminescent polymers.