Visible-light-responsive gels with long-lasting functions via combining metallopolymers and coordination solvents with reduced volatilization

Abstract

Photoresponsive gels exhibit various applications because they can change their structures and properties under the stimulation of light. However, the use of photoresponsive gels is limited by solvent evaporation, which compromises their longevity and functionality. Herein, we design a metallopolymer organogel to overcome this challenge. The organo-gel incorporates metal-ligand coordination bonds as reversible, photoswitchable crosslinks within a polyacrylamide network, using high-boiling-point 1,2-propanediol as the solvent. This system exhibits excellent stability against solvent loss and displays fully reversible and photoresponsive behaviors, including gel-to-sol transitions, color change and volumetric expansion/contraction. We use these properties to demonstrate rewritable photopatterning and shape reconfiguration. We also demonstrate that the organogel maintains low solvent evaporation and stable performance even under hightemperature conditions. The metallopolymer organogel design opens avenues for the development of long-lasting, intelligent soft matter for use in demanding applications.