Force-Induced Near-Infrared Chromism of Mechanophore-Linked Polymers

• DOI: 10.1021/jacs.1c05923
• Publication Date: 2021-09-29T21:40:34Z
• Authors: Qingkai Qi; Gaganjot Sekhon; Richard Chandradat; Nnamdi M. Ofodum; Tianruo Shen; Jan Scrimgeour; Monu Joy; Mario Wriedt; Madhuri Jayathirtha; Costel C. Darie; Devon A. Shipp; Xiaogang Liu; Xiaocun Lu
• Keywords: 02 engineering and technology; 0210 nano-technology

A near-infrared (NIR) mechanophore was developed and incorporated into a poly(methyl acrylate) chain to showcase the first force-induced NIR chromism in polymeric materials. This mechanophore, based on benzo[1,3]oxazine (OX) fused with a heptamethine cyanine moiety, exhibited NIR mechanochromism in solution, thin-film, and bulk states. The mechanochemical activity was validated using UV-vis-NIR absorption/fluorescence spectroscopies, gel permeation chromatography (GPC), NMR, and DFT simulations. Our work demonstrates that NIR mechanochromic polymers have considerable potential in mechanical force sensing, damage detection, bioimaging, and biomechanics.