Science Faculty

Matteo Mauro: LIGHT-RESPONSIVE SUPRAMOLECULAR METALLOPOLYMERS AS SELF-HEALABLE CONTRACTILE MATERIALS

Figure 1. a) Molecular structure of the photo-responsive supramolecular metallopolymers and their schematic synthetic pathway; b) photo-mechanical response of the metallo-organogels under UV irradiation; c) reversible photo-induced expansion/contraction p

Light-responsive supramolecular metallopolymers as self-healable contractile materials

Matteo Mauro

Département des Matériaux Organiques (DMO), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg & CNRS, Strasbourg (France) e-mail: mauro@unistra.fr

Abstract

Smart functional materials that are able to translate an externally applied stimulus into a well defined, controllable, and reversible macroscopic response, such as life-like movements, are one of the most fascinating materials nowadays. On the other hand, soft and structurally dynamic materials are particularly attractive because of their intrinsic possibility to heal after damage. Amongst all possible triggers, light represents an interesting stimulus due to its advantageous features such as remote application with high spatiotemporal resolution.[1] During the talk, the straightforward molecular design of reversible and photo-switchable metallopolymers and their use as photo-responsive and autonomously healable gels will be presented (Fig. 1a).

By simply mixing a proper metal salt and ligand(s) at the desired ratio, libraries of supramolecular metallopolymers have been straightforwardly prepared. In addition, judicious choice of the electronic properties of each building block allows to independently addressing luminescence and photo-isomerization by selection of the excitation wavelength. Such materials can act as “supergelators” and either hydrogels or organogels have been obtained that display light-triggered reversible phase transition[2] and large photo-mechanical response (contraction),[3] respectively (Fig. 1b). Noteworthy, proper choice of the metal ion and its electronic excited-state features, i.e. Fe(II) vs. Co(II) and Zn(II), allowed control of the macroscopic photo-mechanical response in the gels state.[4] Finally, the monitoring of the reversible expansion/contraction processes at the sub-molecular level was achieved by means of scanning tunneling microscopy (STM)[5] on a highly oriented pyrolitic graphite (HOPG) surface (Fig. 1c).

References
[1] M. Mauro, S. Bellemin-Laponnaz, C. Cebrián, Chem.–A Eur. J., 2017, 23, 17626; M. Mauro, Eur. J. Inorg. Chem. 2018, 2090; M. Mauro, J. Mater. Chem. B, 2018, under revision; [2] E. Borré, S. Bellemin-Laponnaz, M. Mauro, Chem.–Eur. J., 2016, 52, 18718; [3] E. Borré, J.-F. Stumbé, S. Bellemin-Laponnaz, M. Mauro, Angew. Chem. Int. Ed., 2016, 55, 1313; [4] E. Borré, J.-F. Stumbe, S. Bellemin-Laponnaz, M. Mauro, Chem. Comm., 2017, 53, 8344; [5] M. El Garah, E. Borré, A. Ciesielski, A. Dianat, R. Gutierrez, G. Cuniberti, S. Bellemin- Laponnaz, M. Mauro, P. Samorì, Small, 2017, 13, 1701790.