Switchable Redox and Thermo-Responsive Supramolecular Polymers Based on Cyclodextrin-Polyoxometalate Tandem

Supramolecular polymers built from stimuli-responsive host-guest interactions represent an attractive way of tailoring smart materials. Herein, we exploit the chaotropic effect of polyoxometalates and related host-guest properties to design unconventional polymer systems with reversible redox and thermo-responsive sol-gel transition. These supramolecular networks result from the association of cyclodextrin-based oligomers and Keggin-type POMs acting as electro-active crosslinking agents. The structure and the dynamics of such self-assembly systems have been investigated using a multiscale approach involving MALDI-TOF, viscosity measurements, cyclic voltammetry, 1H-NMR (1D and DOSY), and Small-Angle X-ray Scattering. Our results reveal that the chaotropic effect corresponds to a powerful and efficient force that can be used to induce responsiveness in hybrid supramolecular oligomeric systems. The chaotropic behavior of polyoxometalates is exploited as an operating principle to promote a reversible and thermo-responsive sol-gel transition of cyclodextrin-based polymer where supramolecular networking results from the host-guest interactions between cyclodextrin-based oligomers and Keggin-type POMs acting as electro-active crosslinking agents. This study reveals that the chaotropic effect corresponds to an effective force able to induce responsiveness into supramolecular materials. image