Vibrational sum frequency generation spectroscopy for interfaces of lanthanide and actinide solvent extractions

Kusaka, Ryoji  

The interfaces of oil and aqueous phases in solvent extractions are the gates for metals to transfer between the two phases. It would be that something special occurs at the interfaces because extractants, which are ligand reagents that facilitate metal transfer into the oil phase by surrounding and stabilizing metals in the oil phase, are surfactants tending to form layers at the interfaces. We have investigated the interfaces of lanthanide and actinide solvent extractions using vibrational sum frequency generation spectroscopy both in homodyne and heterodyne detection methodologies. Vibrational signals of coordinating chemical groups of extractants and interfacial water OH stretch revealed molecular structures of lanthanide and actinide complexes with extractant forming at the interfaces, providing some aspects of phase transfer mechanism of lanthanide and actinide between the oil and aqueous phases.