摘要
A hybrid polymer derived from siloxane and beta-cyclodextrin (beta-CD) was obtained by reaction of beta-CD with gamma-isocyanatopropyltriethoxysilane (IPTS), followed by hydrolysis/condensation reactions, generating a beta-CD-modified polysilsesquioxane resin (PSS-beta-CD). PSS-beta-CD hybrid was characterized by infrared spectroscopy and C-13 and Si-29 nuclear magnetic resonance. This hybrid was typically amorphous and thermally stable up to 180 degrees C. PSS-beta-CD was able to form films and its morphology was evaluated by scanning electron microscopy. The capability of beta-CD grafted in the hybrid polymer to form inclusion complex was evaluated by the formation of a beta-CD-phenolphthalein complex using UV-Vis spectroscopy. Even without changes in pH, the red form of phenolphthalein converts to the colorless one when PSS-beta-CD is immersed in the solution. Theoretical calculations (AM1 and DFT methods) show that the complex is formed through the inclusion of the phenolate ring into beta-CD cavity, favoring the colorless form of phenolphthalein by more than 15 kcal mol(-1).
- 出版日期2010