Covalent organic polyrotaxanes based on β-cyclodextrin for iodine capture.

Herein, covalent organic polyrotaxanes (COPRs) were integrated with supermolecule self-assembly and dynamic imine bond formation to act as absorbents that captured radioactive iodine from water. The aromatic building blocks were initially complexed with β-cyclodextrin (β-CD) to form pseudorotaxanes, which were then condensed with aromatic tri-aldehyde mechanical grinding and solvothermal synthesis in sequence. The threading of β-CD throughout the polymer skeleton effectively reduced the usage of expensive building blocks and significantly lowered the cost, while also remarkably enhancing the skeleton polarity, which is closely related to many special applications. Impressively, the threading of CD improved the water dispersibility of COPRs, which displayed an abnormally high iodine adsorption capacity. This novel synthetic strategy allows the incorporation of mechanically interlocked CDs into porous polymeric materials, which provides access to low-cost preparations of COPRs with a brand new structure for specific applications.