Molar absorption coefficient and radiolytic yield of solvated electrons in diethylmethyl(2-methoxy)ammonium bis (trifluoromethanesulfonyl)imide ionic liquid

金沢大学理工研究域自然システム学系The molar absorption coefficient and the radiolytic yield of solvated electron in ionic liquid of DEMMA-TFSI were estimated respectively to be 2.3×104 L mol-1 cm-1 and 0.8×10-7 mol J-1 by observing the reaction and kinetics of solvated electron and dry electron in the ionic liquid. The solvated electron in DEMMA-TFSI has a very broad absorption spectrum peaking at 1100 nm and reacts slowly with pyrene with a rate constant of 3.5×108 L mol-1 s-1, while the dry electron is captured rapidly by pyrene with C37 value of 0.065 mol L-1. © 2008 Elsevier Ltd. All rights reserved

Picosecond pulse radiolysis: Dynamics of solvated electrons in ionic liquid and geminate ion recombination in liquid alkanes

金沢大学理工研究域自然システム学系A picosecond pulse radiolysis facility based on a laser-driven photocathode electron accelerator has been constructed. First observation of picosecond dynamics in ionic liquid of DEMMA-TFSI in radiation chemistry was reported. It is found that the electrons produced by ionization are solvated to full solvation in ionic liquid with a rate constant of 3.9×1010 s-1, and dry electrons before full solvation react rapidly with biphenyl and pyrene with a rate constant of 3.8-7.9×1011 dm3 mol-1 s-1. The geminate ion recombination in n-dodecane and n-hexane was also observed by monitoring transient optical absorption at 523 nm. © 2008 Elsevier Ltd. All rights reserved

Adsorption behavior of platinum-group metals and Co-existing metal ions from simulated high-level liquid waste using HONTA and Crea impregnated adsorbent

The volume and toxicity of radioactive waste can be decreased by separating the components of high-level liquid waste according to their properties. An impregnated silica-based adsorbent was prepared in this study by combining N,N,N′,N′,N″,N″-hexa-n-octylnitrilotriacetamide (HONTA) extractant, N′,N′-di-n-hexyl-thiodiglycolamide (Crea) extractant, and macroporous silica polymer composite particles (SiO2–P). The performance of platinum-group metals adsorption and separation on prepared (HONTA + Crea)/SiO2–P adsorbent was then assessed together with that of co-existing metal ions by batch-adsorption and chromatographic separation studies. From the batch-adsorption experiment results, (HONTA + Crea)/SiO2–P adsorbent showed high adsorption performance of Pd(II) owing to an affinity between Pd(II) and Crea extractant based on the Hard and Soft Acids and Bases theory. Additionally, significant adsorption performance was observed toward Zr(IV) and Mo(VI). Compared with studies using the Crea extractant, the high adsorption performance of Zr(IV) and Mo(VI) is attributed to the HONTA extractant. As revealed from the chromatographic experiment results, most of Pd(II) was recovered from the feed solution using 0.2 M thiourea in 0.1 M HNO3. Additionally, the possibility of recovery of Zr(IV), Mo(VI), and Re(VII) was observed using the (HONTA + Crea)/SiO2–P adsorbent

Thermochromic properties of low-melting ionic uranyl isothiocyanate complexes

Temperature-dependent yellow-to-red colour changes of uranyl thiocyanate complexes with 1-alkyl-3-methylimidazolium cations have been studied by different spectroscopic methods and this phenomenon is attributed to changes in the local environment of the uranyl ion, including the coordination number, as well as to cation-anion interactions.status: publishe