Study of solvent extraction interfaces using vibrational sum frequency generation spectroscopy; Formation and structure of interfacial complexes between diglycolamide extractants and lanthanide ions

Okudera, Kosuke*; Urashima, Shuhei; Sasaki, Yuji  ; Watanabe, Masayuki   ; Muramatsu, Satoru*; Inokuchi, Yoshiya*; Kusaka, Ryoji  

High-level radioactive waste generated from the reprocessing of spent nuclear fuel contains highly radiotoxic elements, such as americium (Am). Solvent extraction using diglycolamide (DGA) extractants, which act as chelating agents to transfer lanthanide and actinide ions from the aqueous phase to the organic phase, is a promising method for separating radioactive elements and reducing radioactive waste. In this study, vibrational sum frequency generation (VSFG) spectroscopy was employed to investigate the chemical states of DGA extractants at the solvent extraction interface, aiming to gain insights into the transport mechanism of lanthanide ions between the two liquid phases.