Thermodynamics of cyclodextrin-star copolymer threading-dethreading process

Abstract

We investigated the interactions of a star-like copolymer with cyclodextrins (CD) with different cavity size. Direct measurements of thermodynamic properties were done, and the application of proper molecular models was useful for the interpretation of the involved phenomena. The CD-copolymer inclusion complexes were characterized by isothermal titration calorimetry. The copolymer aggregation induced by temperature was investigated by differential scanning calorimetry, volume and compressibility measurements. The behavior of the ternary T1107/CD/water mixture was interpreted considering competing equilibria. The investigated systems showed an interesting temperature responsive behavior so that copolymer-CD necklace-like supramolecular structures are formed, being that temperature raise favors CD dethreading that precedes the copolymer self-aggregation.