Entrapment of Iodine with Cyclodextrins:  Potential Application of Cyclodextrins in Nuclear Waste Management

Cyclodextrins form inclusion complexes with iodine, which makes them candidates for iodine-sorption from nuclear waste gases. In model experiments it was shown that cyclodextrin-containing aqueous solutions and cross-linked cyclodextrin polymers were selective and effective iodine absorbers. Especially the α-cyclodextrin derivatives (methylated and cross-linked) have high sorption capacity. A correlation between the iodine sorption of the cyclodextrin solutions and the apparent association constant of the iodine/cyclodextrin complexes was found. On the basis of the results the binding of elemental and organic iodine emitted into the air by chemical and nuclear power plants can be made effectively by immobilizing iodine vapor in aqueous cyclodextrin solutions or in cyclodextrin polymer gel beds. Such new sorbents can be employed in the air filtration systems.