Threading and Unthreading of Pseudorotaxanes of PEG/Acyclodextrin
Barry J. Bauer, Da-Wei Liu
The threading and unthreading kinetics of alpha-cyclodextrin onto polyethylene glycol is measured by small angle neutron scattering and gel permeation chromatography. The threading is autocatalytic, once threading of a PEG chain is started, it rapidly becomes fully threaded. Fully threaded chains associate, forming a separate phase. Upon heating, dilution, or addition of a good solvent the dethreading is extremely rapid, giving complete dethreading. Since the alpha-cyclodextrin molecule fits closely around a PEG molecule, stearic reasons alone cannot account for slow dethreading of pseutorotaxanes, and other effects such as strong ring-chain interactions must be present.
cyclodextrine, GPC, kinetics, PEG, rotaxane, SANS
and Liu, D.
Threading and Unthreading of Pseudorotaxanes of PEG/Acyclodextrin, Polymer Preprints
(Accessed December 2, 2023)