Title: Mechanochromism and optical remodeling of multi-network elastomers containing anthracene dimers

Authors:

Huan Zhang,   Dezhi Zeng,   Yifei Pan,   Yinjun Chen,   Yonghong Ruan, Yuanze Xu,   Roman Boulatov,   Costantino Creton   and  Wengui Weng

Abstract:

Multi-network elastomers are both stiff and tough by virtue of containing a pre-stretched stiff network that can rupture and dissipate energy under load. However, the rupture of this sacrificial network in all described covalent multi-network elastomers is irreversible. Herein, we describe the first example of multi-network elastomers with a reformable sacrificial network containing mechanochemically sensitive anthracene-dimer cross-links. These cross-links also make our elastomers mechanochromic, with coloration that is both persistent and reversible, because the fluorogenic moiety (anthracene dimer) is regenerated upon irradiation of the material. In proof-of-concept experiments we demonstrate the utility of incorporating anthracene dimers in the backbone of the sacrificial network for monitoring mechanochemical remodeling of multi-network elastomers under cycling mechanical load. Stretching or compressing these elastomers makes them fluorescent and irradiating them eliminates the fluorescence by regenerating anthracene dimers. Reformable mechanochromic cross-links, exemplified by anthracene dimers, hold potential for enabling detailed studies of the molecular origin of the unique mechanical properties of multi-network elastomers.

Published: 26 July 2019

Full Link: https://pubs.rsc.org/en/content/articlelanding/2019/sc/c9sc02580d#!divAbstract