Synthesis of cyclodextrin polymers containing glutamic acid and their use for the synthesis of Ag nanoparticles

Crosslinking and functionalizing agents play crucial roles in the properties/applications of cyclodextrin polymers. Here we report the synthesis of water-insoluble cyclodextrin polymers containing l-glutamic acid. In a first route, β-cyclodextrin was crosslinked with citric acid and subsequently functionalized with l-glutamic acid, while a second route involved esterification of β-cyclodextrin with l-glutamic acid, catalyzed by tin octoate. Combined evaluation by FTIR, ¹³C CP/MAS NMR and elemental analysis indicated that the sample from the first route had the largest fraction of glutamic acid. Sorption tests with methyl orange showed that the cyclodextrin cavities were slightly more available in the polymer obtained through the second route. Samples were employed as reductant and stabilizer for fast and easy synthesis of silver nanoparticles at room temperature. Brief UV irradiation was sufficient for samples produced by the first route.