苯并-15-冠-5/离子液体体系液液萃取锂

以高同位素效应的苯并-15-冠-5(简写为B15C5)为萃取剂,绿色稳定的1-丁基-3-甲基咪唑双(三氟甲烷磺酰)亚胺盐(简写为[C4MIm]NTf2)离子液体为溶剂,建立了B15C5-[C4MIm]NTf2/LiA(阴离子分别为双三氟甲基磺酸亚胺根NTf-2、三氟甲磺酸根OTf~-和Cl~-)-H2O液液萃取体系以高效分离锂同位素。重点考察了体系平衡时间及冠醚浓度、锂盐浓度、温度和pH对分配比D的影响,结果表明:体系萃取平衡较快,t≤30s;提高B15C5浓度和适当降低锂盐浓度有利于分配比D的提高,同等条件下分配比大小为LiNTf2LiOTfLiCl,均远高于其他萃取体系;温度和pH对分配比无显著影响。此外,对络合物晶体的研究发现锂盐与B15C5均形成1∶1络合物[Li4(B15C5)4(OH)2(H2O)](NTf2)2,离子液体体系中Li+可能多数以阳离子交换方式萃入有机相。     

苯并-15-冠-5对小白鼠造血器官的影响

冠醚化合物能促进植物根系吸收并有加速运转无机金属离子的作用,这是由于冠醚化合物对金属离子的络合特性所引起的。我们在实验研究中也发现,某些冠醚化合物在动物体内的代谢特点是易被动物机体所吸收,而又能迅速被排除。因此能否作为疾病诊断上的扫描剂和重金属中毒的解毒及促排剂是值得进一步探讨和研究的。为了深入了解冠醚的毒性以及为探索新药物的合成途径提供科学依据,本文利用同位素示踪法,研究了苯并-15-冠-5对小白鼠造血器管的影响。     

4-叔丁基苯并-15-冠-5液-液萃取法分离锂同位素

本文测定了以4-叔丁基苯并-15-冠-5作络合剂的H_2O/C_6H_51双液萃取体系分离锂同位素的若干参数。发现大环多醚双液萃取锂盐体系的(α—1)对(1—p)有线性关系,α为同位素分离系数,p为有机相的锂/醚浓度比。从ΔG°(交换反应的自由能变化)和ε_p(p=100％时的富集系数)考察,有关体不分离锂同位素能力下降的次序为:穴醚(2,2,1)-CHCl_3/CF_3COOli-H_2O或穴醚(2,2,1)-树脂/LiI-甲醇,(4-叔丁基苯并-15-冠-5)-C_6H_5I/LiSCN-H_2O,(苯并-15-冠-5)-CHCl_3/LiI-H_2O。     

同位素锂盐冠醚络合物的红外位移

利用冠醚分离锂同位素的研究工作已有一些报道。在锂盐冠醚络合物化学交换体系中冠醚结构,特别是冠醚环的大小与锂离子的匹配效应将影响同位素的分离效果。文献[4]中指出,Li~+的晶体半径为6.0nm,而其配位半径为9.0nm,故与15-冠-5(冠醚环半径为8.5—     

溶剂萃取分离锂同位素研究Ⅱ.苏丹Ⅰ-中性配位体协萃体系萃取分离锂同位素效应探讨

文章讨论了苏丹I-中性配位体协萃体系萃取分离锂同位素中螯合剂和协萃剂的结构效应。为了获得高的同位素分离效应,螯合剂必须是弱酸性的(PK_α>11),具有强的分子内氢键及易于形成六元螯合环。协萃剂结构不仅要求无空间位阻,而且具有强的配位基。α随配位基的碱性增大而相应提高。萃取络合物中螯合环的增多亦有利于体系α的提高。此外本文还讨论了一些萃取体系的同位素富集方向和萃锂体系用于分离同位素的前景。     

溶剂萃取分离锂同位素研究——Ⅰ.苏丹Ⅰ-中性配位体协萃体系萃取分离锂同位素效应

文章报导了苏丹I(1-苯基偶氮-2-萘酚)-中性配位体协同萃锂过程中的同位素分离效应。不同协萃剂呈现不同的分离效应,其中苏丹I-TOPO-二甲苯体系的α达1.009±0.001,有机相富集重同位素~7Li。螯合剂,协萃剂和稀释剂对同位素分离效应的贡献作了讨论。实验结果表明螯合剂结构起主要作用,协萃剂结构亦有明显效应,而稀释剂则关系不大。此类体系的萃取和交换平衡速度很快,属于扩散控制的萃取体系。     

离子液体在金属离子萃取分离中的应用

离子液体作为绿色溶剂是溶剂萃取分离金属离子方面研究的热点.介绍了以离子液体为溶剂时,萃取分离各种金属离子的效果,包括碱金属、碱土金属、过渡金属、稀土及锕系金属,以及核燃料后处理涉及的铀、钚及裂变产物等多种离子,深入探讨了其萃取机理.展望了离子液体取代有毒、易挥发、易造成环境污染的有机溶剂的发展和应用前景.     

溶剂萃取分离锂同位素中的阴离子结构效应

本文结合四种锂的离子对萃取体系,从锂络合物结构探讨了与Li~ 对应阴离子结构对同位素分离效应的影响。其中螯合型接触离子对体系和环醚隔离离子对体系呈现明显的阴离子结构效应。前者随着整合阴离子对Li~ 螯合键的增强,有机相富集?~7Li效应增大;后者随着阴离子电荷密度减少和软度增大,不仅有利于萃取分配,而且有利于~6Li的富集。     

Zinc Isotope Fractionation on Benzo-15-crown-5 Resin by Liquid Chromatography

Chromatographic fractionation of zinc isotopes was performed on the synthesized benzo-15-crown-5 resin as a column packing material at 323K in the breakthrough manner for both a frontal and a rear bands. Zinc adsorption capacity was affected by anion chloride concentration and solvent dielectric constant. The heavier zinc isotopes were found enriched to the solution phase and the lighter zinc isotope was concentrated on the resin phase. The frontal maximum enrichment ratio for isotopic pair of ⁶⁸Zn/⁶⁴Zn was 1.0081. The isotope separation coefficients for isotopic pair of ⁶⁸Zn/⁶⁴Zn for frontal and rear band, were 5.3 × 10^?4, 4.5 × 10^?4, respectively.     

Zinc Isotope Effects Observed by Liquid Chromatography with Benzo-15-Crown-5 Resin

The chromatographic fractionation in Zn isotopes was performed on the synthesized benzo-15-crown-5 resin at 313 and 343 K. The lighter isotopes were found enriched in the resin phase. The isotope fractionation coefficients (ε) were 3.4 and 2.9×10^?4, 4.7 and 4.7×10^?4, and 6.7 and 5.7×10^?4 for the ⁶⁶Zn/⁶⁴Zn, ⁶⁷Zn/⁶⁴Zn and ⁶⁸Zn/⁶⁴Zn isotopic pairs at 313 and 343 K, respectively. They reflected mass-dependence among the Zn isotopes at each operated temperature but did not show 1/T² -temperature proportionality. The temperature effects of the composition of Zn species both in the solution phase and in the resin phase may account in part for the latter observation. The magnitudes of ε's in this study were comparable to the ones obtained by ion exchange chromatography, but much smaller than those observed in the solvent extraction systems with a crown ether in the organic phase.     

Study on Liquid-Liquid Extraction of Lithium by Benzo-15-Crown-5/Ionic Liquid System

正By using high isotope effect extracting agent benzo-15-crown-5(B15C5,for short)and green and stable solvent ionic liquid[C_4MIm]NTf_2(Fig.1),liquid-liquid extraction system B15C5-[C_4MIm]NTf_2/LiA-H_2O(anion A was NTf_2~-,OTf~-and Cl~-)was established to separate lithium isotopes efficiently.Based on lots of experimental data,the separation system was proved to     

功能离子液体在镧锕系离子萃取分离中的研究进展北大核心CSCD

离子液体因其独特的物化性质已成为溶剂萃取领域中绿色环保、极具应用前景的稀释剂。除了对萃取剂和萃合物有良好溶解性之外,离子液体萃取体系通过离子交换机理的协同作用,往往还展现出更优的萃取性能。而功能离子液体通常是在离子液体结构基础上进行化学修饰,使其兼具离子液体和螯合基团的双重功能,在萃取过程中不仅能用作稀释剂,还具有萃取作用。近十余年来,功能离子液体在放化分离领域已引起广泛关注。本文首先对离子液体和功能离子液体进行了简介,重点讨论其结构上的关联与区别;再以功能为导向,综述了功能离子液体在铀酰离子、钍离子、镧系和次锕系金属离子萃取分离方面的国内外研究现状,并对功能离子液体在镧锕萃取分离领域的未来研究趋势进行了展望。     

Zinc Isotope Accumulation in Liquid Chromatography with Crown Ether Resin

Liquid chromatographic separation of zinc isotopes was attempted in the breakthrough manner using benzo-15-crown-5 resin as column packing material at 313 K, and a 20 m long development was successfully achieved. The value of the single-stage separation factor was 1.00035 for the ⁶⁶Zn/⁶⁴Zn isotopic pair, 1.00047 for ⁶⁷Zn/⁶⁴Zn pair, and 1.00060 for the ⁶⁸Zn/⁶⁴Zn pair, which were equivalent to those obtained by a 5 m long chromatographic experiment under the same conditions. Contrary to this, the HETP value was 0.19 cm at the 20m development while it had been 0.09 cm at the 5 m development. Connecting separation columns with polytetrafluoroethylene tubes not packed with the resin may be responsible for this migration distance dependence of the HETP.     

离心萃取级联分离锂同位素的数学模型

萃取法分离锂同位素有望替代汞齐法消除汞害,但需多级萃取才能获得高丰度同位素,采用离心萃取机替代萃取澄清槽形成萃取级联系统可提升分离效率。基于萃取法分离锂同位素、离心萃取分离原理和级联理论,借鉴气体离心级联分离同位素的方法,引入分流比概念,建立了离心萃取级联分离锂同位素单级、多级的数学模型和级联的平衡时间模型,对离心萃取级联分离锂同位素进行计算分析。离心萃取级联是一种类似全回流矩形级联形式,取料量对级联级数有着很大的影响,级联存在最大取料丰度限制,级联平衡时间受到目标丰度和离心萃取机级停留时间(处理能力)影响,采用多步法级联可有效减少平衡时间。该数学模型可指导工艺的设计,为下一步的产业化应用提供理论依据。     

Lithium Isotope Separation by Displacement Chromatography Using Cryptand Resin

This paper summarizes results of sensitivity analysis of a generic geologic disposal system for HLW, using a GSRW code and an automated sensitivity analysis methodology based on the Differential Algebra. The results of sensitivity analyses indicate that parameters related to a homogeneous rock surrounding a disposal facility have higher sensitivities to the performance measure analyzed here than those of a fractured zone and engineered barriers.

This methodology permits sensitivity analyses of a single parameter with changing values of other parameters simultaneously, and thus gives quantitative information on the interrelation- ship between the parameters: the parameters for engineered barriers are generally insensitive to the output, while they are somewhat sensitive to the output only in a case of the low solubility condition. The methodology also provides technical Information which might be basis for the optimization of design of the disposal facility.     

离子液体浮选分离模拟乏燃料中的稀土元素

从乏燃料中高效分离稀土元素（中子毒物）是实现乏燃料再生循环利用的关键步骤。利用双有机相离子液体选择性浮选分离乏燃料中的稀土元素,使氧化铀和稀土氧化物几乎不被溶解,实现两者固相之间的分离,避免了二次废液的产生,具有节能和环保的双重意义。以2-乙基己基膦酸单-2-乙基己基酯（P507）为稀土元素的捕收剂、煤油或油酸为稀释剂,以1-丁基-3-甲基咪唑六氟磷酸盐（［C₄mim］［PF₆］）和1-丁基-3-甲基咪唑双三氟甲烷磺酰亚胺盐（［C₄mim］［Tf₂N］）两种离子液体作为浮选体系的另一相,优化得到了浮选分离稀土氧化物的最佳条件。结果发现：浮选分离去除率随着混合物中初始Nd含量以及浮选次数的增加而增加。另外,对所有稀土元素与U₃O₈分别组成的二元体系混合物进行了浮选分离研究,发现在相同条件下,该体系对不同稀土元素的分离也不同,浮选分离的去除率与稀土氧化物的密度有一定的相关性。在此基础上,利用浮选机开展了工艺化的初步探索,发现该浮选体系对Nd的去除率可达80%以上。