Date of Award
Doctor of Philosophy
Howard L. Hall
Robert M. Counce, Lawrence H. Heilbronn, Steven E. Skutnik
Rapid separation techniques for fission and activation products have long been desired to supplant the slow solution-based methodologies currently used. In this work, rare earth elements were derivatized with β [beta]-diketones to synthesize rare earth complexes with high volatility suitable for gas-phase separations. Rare earth elements samarium and dysprosium were combined with hfac (1,1,1,5,5,5-hexafluoro-2,4-pentadione) and fod (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione) and analyzed using a gas-phase separation technique. Rare earth elements praseodymium and europium were combined with dpm (2,2,6,6-tetra-methyl-3,5-heptanedione) and similarly analyzed. Employing the data from the separations, the entropy (Δ [delta] S) and enthalpy (Δ [delta] H) of adsorption were evaluated mathematically based on compound retention within the thermochromatographic test apparatus. New thermodynamic values for enthalpy and entropy of adsorption were calculated as -1±3 kJ/mol and -49±8 J/mol*K for Sm[hfac], 31±8 kJ/mol and 26±16 J/mol*K for Dy[hfac], -20±40 kJ/mol and -94±94 J/mol*K for Sm[fod], 27±4 kJ/mol and 21±10 J/mol*K for Dy[fod], -24±2 kJ/mol and -98±5 J/mol*K for Pr[dpm], and -12±0 kJ/mol and -68±0 J/mol*K for Eu[dpm].
Hanson, Daniel, "Synthesis and Thermodynamic Analysis of Volatile Beta-Diketone Complexes of Select Lanthanides via Gas-Phase Separations. " PhD diss., University of Tennessee, 2014.