Effect of Host-Guest Interaction on Swelling Behavior and Equilibrium Swollen State of Host-Guest Gel

A Host-Guest gel is a supramolecular network formed by the dynamic crosslinking between beta-cyclodextrin and adamantine molecules, and has a novel tough and self-healing properties. In our previous study, we showed that this gel has a topological permanent crosslinking in addition to the dynamic crosslinking, and these two types of crosslinking brings a unique swelling property such as attaining an equilibrium swollen state. In the present study, we examined the swelling behavior and equilibrium swollen states of the Host-Guest gel. The analysis of the swelling process revealed the dynamic crosslinking hardly affect the diffusion on polymer chain under the swelling process. On the other hand, analysis of the equilibrium swollen state with and without a competitor of Guest molecule showed that the dynamic crosslinkings can trap the entanglements of polymer chains even in the equilibrium state because the dynamic crosslinkings are anchored by the permanent crosslinkings and consequently stored in the equilibrium state. These results indicate that the swelling properties of the Host-Guest gels are dominated by both dynamic and permanent crosslinkings in the network.