Time-Resolved Laser-Induced Spectrofluorometry for the Study of Uranium-Anionic Surfactant Micelle Interactions

Time-Resolved Laser-Induced Spectrofluorometry (TRLIS) has been used to study the interaction between surfactants and uranyl ions (UO2+2). Anionic surfactants (CnH2n+1SO-3) of different chain lengths have been investigated in acidic media below and above the critical micellar concentration (CMC) at constant uranium concentration. For comparison purposes, sulfite, short alkylsulfonates of different chain lengths (nonmicellar-forming), and a nonionic surfactant (Triton X100) were also investigated. From lifetime data and by using the Stern-Volmer equation, surfactant quenching constants toward uranium have been obtained. Uranyl quenching constants for the surfactants exhibit high values and differences are observed between short and long chain length alkylsulfonates.