Fabrication of inclusion compounds with solid host γ-cyclodextrins and water-soluble guest polymers:: Inclusion of poly(N-acylethylenimine)s in γ-cyclodextrin channels as monitored by solution 1H NMR

yWe successfully report the formation of poly(N-acylethylenimine)-gamma-cyclodextrin inclusion compounds (PNAI-gamma-CD ICs). The PNAI-gamma-CD ICs were obtained by three techniques: (a) the precipitation of gamma-CD in the polymer solution and (b) and (c) the suspension of as-received cage structure gamma-CD and gamma-CDcs, with a preformed channel structure, respectively, in the polymer solutions. The PNAI-gamma-CD ICs were characterized by solid-state FTIR, X-ray, NMR, DSC, and TGA observations. A H-1 NMR study was performed in order to follow the kinetics of the inclusion process in solution. The time-dependent inclusion of PNAIs with different molecular weights by suspension of either as-received cage structure gamma-CD or channel structure gamma-CDcs in the PNAI solutions was monitored with H-1 NMR. Acetone, a nonsolvent for gamma-CD, was used as the solvent for the PNAI solutions. Some aspects regarding the role water plays in the polymer inclusion process are revealed from our temporal observations of the inclusion of PNAI guests into solid host gamma-CDs.