【作者】 纪杨；

【导师】 马玖彤； 陈继；

【作者基本信息】 吉林大学 ， 分析化学， 2010， 硕士

【摘要】 本文针对季铵类双功能化离子液的制备及其在稀土萃取分离中的应用,开展了四部分工作：1.研究了酸碱中和法制备季铵类双功能化离子液体,并将这种方法与离子交换法进行了对比。同时对所制备离子液的分解温度、密度、含水量及与乙醇、丙酮、庚烷、十二烷、氯仿等有机溶剂的互溶性进行了表征。2.探索了功能化离子液体的内协同效应,以[A336][P204]为例,讨论了双功能化离子液萃取剂[A336][P204]协同萃取铕的研究。利用扩展X射线吸收精细结构光谱(EXAFS)、X射线光电子能谱(XPS)、红外光谱(IR)等对萃取机理进行了研究,同时讨论了反萃实验、[A336][P204]的内协同效应、其他功能化离子液体的内协同效应以及其在稀土分离富集中的应用。3.研究了XAD-7吸附材料的制备方法,并以钪为例研究了其对稀土离子的吸附性能,将由[A336][NO3]和[A336][CA-100]制备的SIR进行对比,证明由[A336][CA-100]制备的SIR具有较高的吸附性能。并进一步探讨了等温吸附作用、平衡时间、解吸附作用等对吸附的影响及Sc3+与Y3+, Ce3+, Eu3+的分离。4.为了克服传统的咪唑类离子液体在萃取过程中的缺点,本文探索了季铵类功能化离子液体[A336][NO3]在稀土分离中的应用,将[C8mim][PF6]与[A336][NO3]的黏度、在高酸度下的稳定性、对钪的萃取效率进行了对比,同时研究了Sc3+与Y3+, Ce3+, Eu3+的分离、钪的萃取机理及钪的循环与反萃。更多还原

【Abstract】 Ionic liquid (IL) is a kind of booming "designer solvents" for a multitude of applications. Their physicochemical properties can be easily tuned by changing combinations of cations and anions. The non-inflammability and non-volatility of ILs provided environment-friendly advantages for using them as replacement to volatile organic compounds (VOCs) in solvent extraction. Moreover, the extraction efficiencies of some IL-based extraction system are higher than those of VOC-based system. As the development of ILs, TSILs have emerged. The TSILs contain functional groups for task-specific purpose in their cation and/or anion, which can be "tailor-made" preparation for some separation processes.The common synthetic route of ILs is anion metathesis reaction, which is achieved by metathesis reactions between halide intermediates of ILs and appropriate acids or salts. However, ILs prepared by anion metathesis reaction are always contaminated by halide and alkali metals ions, the contamination is detrimental to biology, synthesis, electrochemistry, catalysis and spectroscopy. To get IL with desired quality, we report herein a simple strategy is acid/base neutralization method. Physicochemical properties of the bifunctional TSILs, i.e. density, water content, decomposition temperature, munal solubility, are also studied in this paper.As the development of ILs, TSILs containing functional groups come to be series of liquid functional materials. In view of extraction requirement, it is our purpose to design TSILs as high-efficient extractants. Synergistic effect in solvent extraction is attributed to combined coordinating/solvating abilities of two extractants are better than their simple sum of individual contributions. Recently, a series of ILs derived from tricaprylmethylammonium chloride (A336) have attracted attention. A336 was widely used as extractant in solvent extraction. To further enhance the extraction capacity of A336, we develop some novel Bif-ILEs by combining the cation of A336 with phosphonic acid group or carboxylic acid group as anions. The synergistic effect comes from both cations and anions of TSILs, we call it "inner synergistic effect". in this paper, we study [tricaprylmethylammonium][di-2-ethylhexylphosphinate] ([A336][P204]) as an extractant for Eu(III), which can be attributed to better stability and hydrophobicity of the complex formed by [A336][P204] with Eu(III).However, bigger viscosity of the TSIL is a disadvantage for its application in liquid-liquid extraction, which will result in lower rate of mass transfer, the loss of their cation and anion to aqueous phase. Solid-liquid extraction seems to be a more advisable method for its application in separation. [trialkylmethylammonium] [sec-nonylphenoxy acetate] ([A336][CA-100]) are impregnated on intermediate polaritied XAD-7 resin in this paper, and the prepared solvent impreganated resin (SIR) was studied for rare earths (REs) separation. Adsorption ability of the SIR is indicated to be obviously higher than that prepared by [A336][NO3] since the functional anion of [A336][CA-100]. Adsorption kinetics, adsorption isotherm, separation and desorption of the SIR are also studied in this paper.Ammonium-type ILs have attracted considerable attention because their costs are much cheaper than those of imidazolium-type IL. Moreover, the toxicity of ammonium-type IL is lower than those of imidazolium-type IL and organic solvents. In additional, some quaternary ammonium salts have well applied background in solvent extraction. In this paper, we study Cyanex925-[A336][NO3] system for REs separation. In compare to [Cgmim][PF6], the TSIL reveal many advantages for IL-based extraction, i.e., lower cost, lower toxicity, lower density than water, stability on acidic condition, solvating mechanism, easy to be stripped, regenerated and recycled.更多还原