Supramolecular Organogel Based on Crown Ether and Secondary Ammoniumion Functionalized Glycidyl Triazole Polymers

Abstract

A supramolecular organogel was prepared by mixing the glycidyl triazole polymers (GTP) functionalized with crown ether and secondary ammoniumion at the side groups. The polymers form an organogel above a concentration of 3 wt % via physical cross-links of the inclusion complex. The organogel responds to multiple stimuli, e.g., temperature, acid/base, and chemical species. The number of the effective cross-links estimated from the storage modulus and the affine network model suggests that some part of the binding sites could not work as the physical cross-links. Rheological measurement under large deformation showed that the storage modulus was constant up to 250% strain and larger than the loss modulus up to 600% strain. The high elasticity of the gel is attributable to the material design based on the high-molecular-weight flexible glycidyl polymers with many binding sites in the single polymer chain. The organogel also showed nice self-healing behavior. The molecular diffusion in the gel network was characterized by fluorescence correlation spectroscopy. Although the cross-link of the organogel has dynamic nature due to inclusion complexation, the diffusion behavior of the low-molecular-weight fluorescence tracer was similar to that observed in chemically cross-linked gels.