Tuning the Extractive Properties of Purex Solvent using Room Temperature Ionic Liquid

An Aliquat-336 based ionic liquid, namely, tri-n-octylmethylammonium bis(2-ethylhexyl)phosphate ([A3636]⁺[DEHP]^?) was prepared and studied for the extraction of U(VI), Pu(IV), and Am(III) from nitric acid medium. Since the ionic liquid, [A336]⁺[DEHP]^? was miscible in n-dodecane (n-DD), the extraction of these actinides in the PUREX solvent, 1.1 M tri-n-butylphosphate (TBP) in n-dodecane (n-DD), was investigated in the presence of small concentrations of ionic liquid. The distribution ratio of U(VI) and Am(III) in 0.03 M [A336]⁺[DEHP]^?/n-DD decreased with increase in the concentration of nitric acid; whereas the extraction of Pu(IV) initially increased, it reached a maximum at 4 M nitric acid followed by the decrease. The extraction of actinides in ionic liquid medium decreased in the order Pu(IV) > U(VI) >> Am(III), indicating the feasibility of modifying the extractive properties of TBP/n-DD to favor Pu(IV) extraction. Therefore, the extraction of Pu(IV) in a solution of TBP – [A336]⁺[DEHP]^? in n-DD was also studied. The distribution ratio of Pu(IV) increased with increase in the concentration of ionic liquid and decrease in the concentration of TBP in organic phase. The distribution ratio of Pu(IV) determined in the presence of small concentration of ionic liquid in 1.1 M TBP/n-DD was always much higher than that observed in 1.1 M TBP/n-DD. In contrast to this, the distribution ratio of U(VI) decreased by the addition of ionic liquid and Am(III) was inextractable even in the presence of ionic liquid.     

Extraction of Uranyl Ion Using 2-Thenoyltrifluoro Acetone (HTTA) in Room Temperature Ionic Liquids

The extraction of UO₂²⁺ ion was studied using six different solvent systems containing 2-thenoyltrifluoroacetone (HTTA) in room temperature ionic liquids such as [C_nmim][X] (where, n = 4, 6, or 8 and X^? = PF₆^? or NTf₂^?) from low to moderate pH solutions for the first time. The extraction kinetics studies indicated rather slow attainment of equilibrium which in some cases improved if the solutions were pre-equilibrated with the aqueous phase prior to the actual experiments. The D_U values were found to increase with increasing pH and leading to a plateau like profile at higher pH values. The D values were quite high as compared to that obtained with molecular diluents. The nature of the extracted species was ascertained by slope analysis method which suggested species of the type: UO₂(TTA)⁺_IL, UO₂(TTA)_2,IL, and UO₂(TTA)₂(HTTA)_IL in different ionic liquid based solvents. Temperature variation studies on UO₂²⁺ ion extraction were also carried out and the thermodynamic parameters were calculated which indicated high endothermicity of the reactions with large positive entropy values.     

Extraction of Azo Dyes from Aqueous Solutions with Room Temperature Ionic Liquids

In this work, ionic liquids/water distribution ratios (D) of azo dyes, including 1-(phenylazo)-2-naphthol, 1-(2-pyridylazo)-2-naphthol, 4-(nitrophenylazo)resorcinol, 4-(2-pyridylazo) resorcinol, and 2-(4-dimethylaminophenylazo) benzoic acid, have been determined experimentally. It was found that the D values are highly influenced by the pH of the water phase and the type of salts added. They increase with increasing alkyl chain length on the cations of the ionic liquids, and the anionic effect follows the order [BF₄]^? > [PF₆]^?. Possible extraction mechanism and selective separation of some azo dyes are also investigated. The results suggest that ionic liquids have potential applications in the removal and selective separation of azo dyes from water.     

室温离子液体在化学合成和萃取分离中的应用

简要介绍了室温离子液体的特性、制备方法,并着重讨论了室温离子液体在化学合成和萃取分离等方面的 应用及研究进展。     

室温离子液体的应用

介绍了室温离子液体作为一类绿色溶剂和催化剂体系在分离过程、化学反应、电化学等领域的应用情况;同时离子液体还可以作为润滑材料、敏感材料、储能材料和光学材料.分析了在离子液体研究过程中存在的问题,展望了离子液体的应用前景.     

Studies on the Extraction of Actinides by Diamylamyl Phosphonate

Abstract

Diamylamyl phosphonate (DAAP) was synthesised by the Michealis Becker reaction, and was characterized by elemental analysis, IR, and ³¹P NMR. The extraction of U(VI), Th(IV), Pu(IV) and Am(III) by 1.1 M DAAP in n‐dodecane as a function of nitric acid concentration was studied and the results are compared with the extraction behavior of these ions by tributyl phosphate (TBP) and triamyl phosphate (TAP) in n‐dodecane. Some important physical properties of the extractant that have to be met for its use in industrial scale liquid‐liquid extraction such as density, surface tension, viscosity and phase disengagement time with 1.1 M DAAP/n‐dodecane have been measured and compared with those of 1.1 M TBP/n‐dodecane. Studies on the third phase formation behavior of DAAP/n‐dodecane with U(VI) and Th(IV) nitrates in nitric acid medium have been carried out and the results are reported. The breakthrough and elution behavior of U(VI) using a column packed with 50% (w/w) DAAP impregnated on Amberlite XAD‐7 was studied and reported.     

离子液体在萃取有机物方面的应用

近些年来,世界各国学者对离子液体的研究越来越多,随着对离子液体研究的深入,离子液体的应用逐渐渗透到各个领域中。主要介绍近年来离子液体在萃取有机物方面的应用进展。     

Ionic Liquid Extractants in Molecular Diluents: Extraction Behavior of Plutonium (IV) in 1,3-Diketonate Ionic Liquids

Abstract

Room temperature ionic liquids (RTILs) containing β-diketonate anions have been prepared and studied for the extraction of ²³⁹Pu(IV), ²³³U(VI), and ²⁴¹Am(III) from nitric acid medium. The ionic liquids such as alkylquaternaryammonium thenoyltrifluoroacetonate (R₄NTTA), and 1-alkyl-3-methylimidazolium thenoyltrifluoroacetonate (amimTTA), with methyl, butyl, hexyl, heptyl, and octyl moieties have been prepared and characterized by ¹H and ¹³C nmr and IR spectroscopy. The distribution ratio of plutonium(IV) (D _Pu(IV)) in a solution of tri-n-octylmethylammonium thenoyltrifluoroacetonate (TOMATTA) present in tri-n-octylmethylammonium bis(trifluoromethylsulfonyl)imide (TOMANTf₂) and amimTTA in amimNTf₂ was studied as a function of various parameters. The unique property of β-diketonate ionic liquids, namely, the miscibility in molecular diluents, was exploited to elucidate the mechanism of Pu(IV) extraction in these ionic liquids.     

疏水性离子液体用于萃取酚类物质

测定了苯酚、苯基酚、苯二酚等几种不同取代基的酚类物质在疏水性离子液体[bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐)和[dmim]PF6(1-癸基-3-甲基咪唑六氟磷酸盐)与水两相中的分配系数. 实验结果表明,萃取过程很快可以达到平衡. 与传统有机溶剂相比,分配系数处在同一个数量级. 分配系数随温度升高而降低,离子液体对不同取代基的酚类萃取能力有很大差异,咪唑基团上取代烷基链的长度对不同酚类物质的分配系数有很大影响,因此可以通过调节离子液体结构使其适用于不同成分的含酚废水.     

室温离子液体的合成及其在催化烷基化反应中的应用

离子液体具有很多独特的物理、化学性质,正引起人们越来越多的重视,被认为是一类可以取代传统有机溶剂对环境友好的新型绿色溶剂,在很多领域中有着诱人的应用前景。本文归纳了离子液体的优越性质,介绍了离子液体的组成和制备方法,综述了其作为催化剂在烷基化反应中的应用,并展望了离子液体在该领域中的应用前景。     

室温离子液体在萃取中的应用

综述了室温离子液体在萃取中的应用研究,包括液—液萃取,液相微萃取,固相微萃取,超临界CO2萃取。     

Extraction of Metal Ions with Task Specific Ionic Liquids: Influence of a Coordinating Anion

Hydrophobic ionic liquids (ILs) were generated by association between a cationic ester derivative of betaine and bis(trifluoromethylsulfonyl)imide (Tf₂N^?) or dicyanamide (Dca^?) anions. Extraction of Cu(II), Ni(II), Pb(II), and Cd(II) from water was performed with these ILs at room temperature. The use of Dca^? anion greatly enhances the extraction efficiency of IL phase towards metal ions extraction. The metal could be back-extracted from the ionic liquid phase with aqueous EDTA solutions. The metal extractability of the ionic liquid after the back-extraction is equivalent to that of the fresh mixture showing that ionic liquid can be reused for several extraction and back-extraction cycles.     

室温离子液体在石油化工中的应用

介绍了室温离子液体的制备及物理性质,详细说明了室温离子液体在石油化工中的应用,如在烷基化、氢化、脱硫、C-C偶联等反应中的应用;分析了室温离子液体现存的缺点.最后,提出室温离子液体工业应用的方向及可能存在的问题.     

离子液体用于金属离子萃取的研究进展

作为一种重要绿色溶剂的离子液体,因其具有独特的物理化学特性,故其在分离领域的研究一直处于活跃状态。本文介绍了离子液体作为稀释剂应用于金属离子萃取分离过程的研究进展,着重梳理讨论了含有萃取剂的离子液体萃取体系中阳离交换和阴离子作用两种萃取机理。     

室温离子液体在化学合成和萃取分离中的应用

室温离子液体被认为是一种多功能的新型绿色溶剂,其应用十分广泛。简要地介绍了室温离子液体的特性、制备方法,并着重讨论了室温离子液体在化学合成和萃取分离等方面的应用及研究进展。     

具有羧酸官能团的功能性离子液体萃取分离钇的研究(英文)

A new kind of hydrophobic ionic liquids [1-alkyl-3-(1-carboxylpropyl)im][PF6] has been synthesized,and their extraction properties for Y(III) in the nitric acid medium was also investigated.The effects of extractant concentration,equilibrium pH of aqueous phase,salt concentration,temperature etc.were discussed.The results show that this kind of Task-Specific Ionic Liquid(TSIL) needs to be saponified before being used for the Y(III) ex-traction,and the extraction is acid dependent,and the extraction efficiency increases with the aqueous phase acidity decreasing.Furthermore,the loaded organic phase is easy to be stripped;more than 95% Y(III) could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol?L?1.The slope analysis technique is used to investigate the extraction mechanism,and a possible cation-exchange extraction mechanism is proposed in the present extraction system.     

离子液体在萃取分离中的应用

在查阅了大量的国内外文献资料的基础上,介绍了近几年离子液体研究应用的进展。综述了离子液体在萃取分离过程中的应用,并展望了离子液体在分离方面的应用前景和发展方向。     

室温离子液体在催化及有机反应中的应用

简述了室温离子液体在氢化反应、氧化反应和酯化反应等有机反应中作为催化剂和溶剂的应用。指出室温离子液体具有熔点低、有较宽的液态范围(大约300℃)、很强的溶解能力、良好的酸性并在很大的范围内可调、几乎没有蒸气压、高极性、较宽的电化学窗口和较好的热稳定性和化学稳定性等独特性能,可以重复使用。     

室温离子液体的研究进展

室温离子液体具有较低的熔点、良好的导电性和可以忽略的蒸汽压等优点，引起了科学界和工业界的广泛瞩目。近年来，随着研究的日益深入，室温离子液体已经被开发和应用到诸多领域。本文对室温离子液体的合成、结构、性能及应用等方面的研究进展进行了综述。     

Prediction of Selective Extraction of Cresols from Aqueous Solutions by Ionic Liquids Using Theoretical Approach

This work reports the prediction of selective extraction of cresol from aqueous solutions using ionic liquids (ILs) as the solvent. Judicious screening of various ILs was carried out for all the three forms of cresol (i.e., o-cresol, m-cresol, and p-cresol). A quantum chemical based theoretical model “conductor-like screening model for real solvents” (COSMO-RS) was used to predict the selectivity of cresol in aqueous medium at infinite dilution. A screening of 360 possible ILs from 15 cations and 24 anions was carried out to determine the best IL for the removal of cresol from water. Amongst the phosphonium and imidazolium based cations, trihexyl tetradecylphosphonium [THTDP] and 1-octyl-3-methylimidazolium [OMIM] gave the highest selectivity other than the anions bromide and chloride. The selectivities for different cresols followed the pattern: m-cresol > p-cresol > o-cresol. Similarly for pyridinium and quinolium based cations, 1-ethylpyridinium [EPY] and 1-octylquinolium [OQU] gave the highest selectivity. Amongst the two cations studied for pyrrolidinium based cations, 1-hexyl-1-methylpyrrolidinium [HMPL] was the best. Trihexyl tetradecylphosphonium salicyclate [THTDP][SAL] gave the highest selectivity of 662 amongst all the ILs screened.