Unravelling Competitive Interactions between Polymer Side Chains and End Groups with β-Cyclodextrin

This study investigates unexpected competitive host-guest interactions of beta-cyclodextrin (beta-CD), which can occur with polymers in aqueous solution, using the examples of the two polymers poly(oligo(ethylene glycol) methyl ether methacrylate) and poly(glycerol mono methacrylate). Systematic structural modifications of the polymer provide insight into the host-guest interaction with beta-CD and the competition between side chains and end groups such as hydrophobic end groups remaining from reversible addition fragmentation chain transfer polymerization or intentionally implemented molecular recognition units such as arylazopyrazole photoswitches. Competitive host-guest interactions in aqueous solution of beta-cyclodextrin with side chains and end groups of two hydrophilic polymers are investigated. Structural modification of the polymers, including the implementation of photoswitches, and detailed analysis by isothermal titration calorimetry provide insights into the balance of supramolecular interactions. image