Relationships between chemical shift and structure of Cs absorbed on clay mineral

Takei, Koyo*; Okubo, Takahiro*; Tachi, Yukio; Fukatsu, Yuta

no journal, , 

Cs adsorption sites on vermiculite clays were investigated by Cs magic-angle-spinning nuclear magnetic resonance (MAS NMR) and theoretical Cs chemical shift calculations. A partially Cs exchanged vermiculite sample was prepared. Three peaks on Cs MAS NMR spectra were experimentally observed. However, Cs absorption sites were not assigned to these peaks. A molecular model of fully Cs exchanged vermiculite was built to obtain Cs chemical shift theoretically by GIPAW method. Calculated Cs chemical shift ranged 23 to 47 ppm, which corresponds to the peak of the lowest field side. Detailed relationships between structure and Cs chemical shifts were investigated from Cs position and vermiculite layer structure.