Christian G. Bustillos, Randy Ngelale, Mikael G. Nilsson
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引用次数: 0
Abstract
ABSTRACT Organic solutions comprising the Actinide Lanthanide Separation Process (ALSEP) solvent consisting of 0.5 M 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and 0.05 M N,N,N’,N’-tetra(2-ethylhexyl)diglycolamide (T2EHDGA) in n-dodecane were subjected to low LET and high LET irradiation before and after equilibration with an aqueous phase of 3 M HNO3. Degradation dose constants revealed greater ligand degradation due to gamma irradiation than alpha irradiation for both ligands. Furthermore, equilibration with nitric acid did not have a significant impact on ligand degradation for either irradiation source. Identified degradation products were similar for both gamma and alpha irradiation and occurred mostly through the rupture of the N–Ccarbonyl and C–Oether bonds for T2EHDGA and the C–Oether bond in HEH[EHP]. Acid contact appears to alter the degradation pathway by favoring the formation of higher molecular weight recombination products. Mixed T2EHDGA-HEH[EHP]-NO3 complexes were formed with Nd(III) after extraction from 3 M HNO3, and low LET gamma irradiation of the Nd(III) loaded organic solution produced similar degradation products as the organic solution absent of Nd(III). Interestingly, and likely due to the greater radiolytic susceptibility of T2EHDGA than HEH[EHP], a HEH[EHP]-Nd(III) complex appears to form as the T2EHDGA degrades with increasing absorbed dose.
摘要包含锕系元素-镧系元素分离工艺(ALSEP)溶剂的有机溶液,该溶剂由0.5 M-2-乙基己基膦酸单-2-乙基己基酯(HEH[EHP])和0.05 在用3 M HNO3。降解剂量常数显示,对于两种配体,由于γ辐射而导致的配体降解大于α辐射。此外,用硝酸平衡对两种辐射源的配体降解都没有显著影响。已鉴定的降解产物在γ和α辐照下相似,主要通过T2EHDGA的N–C羰基和C–Oether键以及HEH[EHP]的C–Oether键断裂发生。酸接触似乎通过有利于形成更高分子量的重组产物来改变降解途径。Nd(III)从3 M HNO3和负载Nd(III)的有机溶液的低LET伽马辐射产生与不存在Nd(Ⅲ)的有机溶剂类似的降解产物。有趣的是,很可能是由于T2EHDGA比HEH[EHP]更大的放射分解敏感性,随着T2EHDGA随着吸收剂量的增加而降解,似乎形成了HEH[EHP]-Nd(III)复合物。
期刊介绍:
Solvent Extraction and Ion Exchange is an international journal that publishes original research papers, reviews, and notes that address all aspects of solvent extraction, ion exchange, and closely related methods involving, for example, liquid membranes, extraction chromatography, supercritical fluids, ionic liquids, microfluidics, and adsorption. We welcome submissions that look at: The underlying principles in solvent extraction and ion exchange; Solvent extraction and ion exchange process development; New materials or reagents, their syntheses and properties; Computational methods of molecular design and simulation; Advances in equipment, fluid dynamics, and engineering; Interfacial phenomena, kinetics, and coalescence; Spectroscopic and diffraction analysis of structure and dynamics; Host-guest chemistry, ion receptors, and molecular recognition.