[2C15-20] Migration/Sorption2

[2C19] Hydration state of Eu adsorbed in small pores

*Kento Murota^1,2, Noboru Aoyagi³, Huiyang Mei³, Takumi Saito¹ (1. UTokyo, 2. NRA, 3. JAEA)

Keywords:Adsorption, Times-resolved laser fluorescence spectroscopy, Eu, Mesoporous silica, hydration

In the dynamics of radionuclides leached from radioactive wastes in the underground, adsorption of radionuclides to nanopores in rocks and buffer materials is an important mechanism. We have analyzed Eu³⁺ adsorbed on mesoporous silica by time-resolved laser fluorescence spectroscopy (TRLFS) and reported in the last meeting that the asymmetry of the coordination environment of Eu³⁺ increases as the pore size decreases. In this meeting, we report the results of TRLFS analysis of Eu³⁺ adsorbed on mesoporous silicas with mesopores of different diameters and a silica without pores with different percentages of light water, to investigate the effect of pore size on the adsorption structure including the hydration state of Eu³⁺ based on differences in fluorescence lifetime.