【作者】 耿彦霞；

【导师】 吴王锁；

【作者基本信息】 兰州大学 ， 无机化学， 2011， 博士

【摘要】 由于镧锕系收缩使得三价的镧系和锕系元素的物理化学性质非常相似,分离十分困难,是分离化学领域中的难题之一。本文就金属离子的萃取分离方法进行了概述,主要总结了溶剂萃取、固相萃取及分子印迹技术的基本原理、特点及应用,概述了溶剂萃取及固相萃取在镧锕系元素分离方面的研究进展。本论文主要以Eu(Ⅲ)与Am(Ⅲ)为代表的三价镧锕系元素的萃取分离为目的,合成了多种萃取分离材料,并就其对Eu(Ⅲ)与Am(Ⅲ)的分离性能能进行了初步探讨。具体内容主要包括以下两个方面：一、以实现Eu(Ⅲ)与Am(Ⅲ)的溶剂萃取分离为目的,合成了两类不同的萃取剂：(1)合成了多种水杨醛系列席夫碱,详细研究了双水杨醛缩乙二胺、邻苯二胺及环己二胺席夫碱对Am(Ⅲ)和Eu(Ⅲ)的萃取分离性能,推测了其与金属离子的作用机理,在此研究基础上,我们从两醛分子之间桥连链长,两醛分子之间桥连链刚性和醛分子上取代基三方面研究了该类芳香席夫碱分子作为萃取剂时,其分子结构对Am(Ⅲ)和Eu(Ⅲ)萃取能力的影响,并对其结果进行了规律总结。(2)基于胺类良好的耐辐射性能,我们合成了一种三支叔胺配体,并得到了该配体及其中间体的单晶,并对晶体结构进行了解析,推测了配体的生成机理,测定了该三支配体对Am(Ⅲ)和Eu(Ⅲ)的萃取分离性能,发现只有在高pH值时,该配体才对Am(Ⅲ)和Eu(Ⅲ)有萃取分离能力且在pH=12时萃取分离能力最强。这可归因于在该三支配体中存在较强的分子内或分子间氢键。二、以实现Am(Ⅲ)和Eu(Ⅲ)的固相萃取分离为目的,合成了四类不同的固萃剂,包括：(1)高分子负载型固萃剂：通过共沉淀法,以FeSO4·7H2O和FeCl3·6H2O为原料,以氨水为沉淀剂,在一定温度条件下制备了磁性纳米四氧化三铁,并进一步以硅酸钠为硅源采用化学沉淀法制备了Fe3O4/SiO2复合颗粒,并对制备的Fe304及Si02包覆的Fe304复合产物进行了表征。利用X射线衍射分析测定了其结构为尖晶石结构,利用振动样品磁强计研究了纳米四氧化三铁的磁学性质。结果表明,所制备的Fe304及Fe3O4/SiO2纳米颗粒均未出现明显磁滞现象,剩余磁化强度及矫顽力均接近于零,说明产物具有超顺磁性；应用超声波技术,以氯丙基三甲氧基硅烷为偶联剂,以普通硅胶、纳米Si02及磁性硅胶为载体,在温和条件下制备了嫁接型双水杨醛缩二乙烯三胺席夫碱和其还原产物,并对相应产物进行了结构表征；利用接枝在表面的席夫碱及还原席夫碱易与金属离子发生配位作用的特点,将其作为固相萃取吸附剂,初步测定了其对Eu(Ⅲ)的固萃分离性能,结果表明普通硅胶、纳米Si02及磁性硅胶负载席夫碱后对Eu(Ⅲ)的固萃性能均有提高。(2)金属离子印迹类固萃剂：以4-乙烯基吡啶为功能单体,以Eu(Ⅲ)为模板离子,分别以N-苯基邻氨基苯甲酸、1-(2-吡啶偶氮)-2-萘酚(PAN)和2-((allyl(benzyl)amino)methyl)phenol(实验室合成)为第二配体,制备了三种Eu(Ⅲ)离子印迹聚合物,结构表征显示,制备的三种三元聚合物微球形貌均较好,粒径分散较均匀,BET测定显示以N-苯基邻氨基苯甲酸为第二配体的离子印迹聚合物比非印迹聚合物的比表面大很多,通过对Eu(Ⅲ)的固相萃取性能的测定,发现印迹聚合物对Eu(Ⅲ)的吸附性能强于非印迹聚合物(3)表面离子印迹类固萃剂：以N-苯基邻氨基苯甲酸为第二配体,分别以纳米二氧化硅和磁性硅胶为载体,制备了Eu(Ⅲ)的表面离子印迹聚合物,对聚合物结构进行了表征,并初步考察了其对Eu(Ⅲ)的萃取分离性能。实验结果显示,相同条件下印迹聚合物对Eu(Ⅲ)的固萃性能优于非印迹聚合物(4)海藻酸钙杂化材料固萃剂：为了得到一种安全清洁的金属离子处理剂,我们以海藻酸钙为基质制备了海藻酸钙/磁性硅胶,海藻酸钙/氧化碳纳米管,海藻酸钙/氧化碳纳米管/磁性硅胶三种杂化材料,磁性测定表明海藻酸钙包覆后磁性硅胶的磁化强度降低非常多,还考察了其对Eu(Ⅲ)的分离性能,实验结果显示不同的包覆杂化对Eu(Ⅲ)的吸附能力有一定影响。更多还原

【Abstract】 The separation of trivalent actinides ((An (Ⅲ)) from lanthanides cations ((Ln(Ⅲ)) is difficult because of the similar chemical properties, such as ionic radii and oxidation states, thia caused by the lanthanide and actinide’ constriction. In this pape we reviewed the ectraction separation method of metal ions, introduced the mechanism, the characteristic and the application of solvent extraction, solid phase extraction and the ion-imprinting method. We reviewed the development of study on separation.In this paper, we have synthesized several materials as extractants and investigated their extracton ability for Am(Ⅲ) and Eu(Ⅲ), this paper include two sections1. (1) N, N’- bis(salicilidene)ethylenediamine (H2salen)- and its derivatives were investigated as extractants for the separation of Am(Ⅲ) and Eu(Ⅲ). As results, H2salen is effective extractant for the mutual separation of Am(Ⅲ) and Eu(Ⅲ) under the experiment conditions. The maximum SFAm/Eu of 96 was obtained in the extraction system using nitrobenzene as diluent. Eu(Ⅲ) can be extracted from hydrochloric acid solution in the different form M (H3salen)·Cl4, M (H2salen)Cl3 and M (salen)Cl at different pH by H2salen/nitrobenzene. And yet Am (Ⅲ) can be extracted from hydrochloric acid solution in M(H2salen)Cl3 only. The effect of molecular structure of four ligan on the extraction for Am (Ⅲ) and Eu(Ⅲ)were studed. The extacion of Am (Ⅲ) and Eu (Ⅲ)from 0. 1 mol/L LiCl medium with these schiff base ligands in chloroform, as the results showed that the order of extraction ability for Am(Ⅲ) and Eu(Ⅲ) is sci4>sci2>sic3>schiff baseⅠ> schiff baseⅡ, and the extraction selectivity for Am(Ⅲ) is sci4> schiff baseⅠ> sic3> sci2. The obtained maximum separation factors (SFAm/Eu) are 9.4,2.8,2.5,2.1. Sci4 was thus chosen as an extractant to detected the effect of concentration on Am(Ⅲ) and Eu(Ⅲ)extraction from acid solution and the content of the coordination complex were deduced, sci4 conplexed with Eu(Ⅲ) in form 1:1, with Am(Ⅲ) in form 2:1 or 3:1.(2) A tripodle ligand was synthesised and crystal structure of tripod liand and a intermediate product were obtained. The reaction mechanism of the tripod was proposed. As extractant for Am(Ⅲ) and Eu(Ⅲ) the tripod ligand was studied, as the result showed that the ligand could extract Am(Ⅲ) and Eu(Ⅲ) only at high pH.2. (1) he Fe3O4 magnetic nanoparticles were synthesized by chemical coprecipitation of FeSO4·7H2O and FeCl3·6H2O in ammonia solution at a certain temperature. Then, silica was coated on the surface of Fe3O4 nanoparticles using a chemical precipitation method of sodium silicate. The X-ray diffraction(XRD) of Fe3O4 demonstrated that the magnetic nanoparticle was Fe3O4 and the structure of the magnetite nanopartides is spinel, According to the image of Fe3O4/SiO2 by TEM, the morphology is obviously core-shell structure, and the vibrating sample magnetometer(VSM) showed that magnetic materials was superparamagnetic as their magnetization and coercive force are almost zero. Schiff base ((1E,N1E)-N1-benzylidene-N2-((E)-2-((E)-benzylideneamino)vinyl) ethene-1,2-diamine) modified SiO2 were prepared with 3-chloropropyl trimethoxysilane (CPTMS) as coupling agents with ulrasonic technique under mild conditions. The samples were characterized by IR spectroscopy, XRD, TGA and Magnetic hysteresis loop(2)Three molecularly imprinted polymeric microspheres (MIPMs) were prepared by suspension polymerization method in aqueous system using Eu (Ⅲ) as ion-printing template, N-Phenylanthranilicacid,1-(2-pyridiny lazo)-2-Naohthalenol and-((allyl(benzyl)amino)methyl)phenol as coordination ligand, respectively,4-vinylpyridine as functional monomers and Divinylbenzne as cross-linker, The morphology including the size, size dist ribution, pore and pore dist ribution of the polymer beads was analyzed by BET analysis. The molecule selecting property of the Eu (Ⅲ) ions was detected through statics liquid method. The results showed that uniform-sized spherical IIPMs had been prepared in aqueous system by suspension polymerization method, the printing molecules selectively.(3) combining the high selectivity and good mass transport of surface molecular imprinting technique, high surface-to-volume ratio of nanoparticles and speediness of magnetic separation, two kinds of novel core—shell surface molecularly imprinted nano-composite system were synthesized for separation and recognition of Am(Ⅲ) and Eu(Ⅲ) using surface imprinting technique. .N-Phenylanthranilic acid and 4-vinylpyridine, which are the coordination ligand and functional monomer respectively and divinylbenzne (DVB) as cross-linking monomer, EuCl3·6H2O as template and then ion-imprinted thin films were coated onto the nano-silica or silica-modified Fe3O4 nanoparticle’s surface through oxidation with AIBN in organic solution. The morphology and recognition properties of the surface ion-imprinted nanomaterial were investigated by transmission electron microscopy(TEM), X-ray diffraction(XRD), thermogravimetric analysis(TGA), vibrating sample magnetometer(VSM) and the recognition mechanism of template ion identification Was discussed. The Eu(Ⅲ) ion adsorption results showed that Eu(Ⅲ) ion-IP-coated silica or magnetic nanoparticles have high adsorption capacity for template ion due to specific recognition sites for template metal ions on the imprinted shell make this nanoparticles with specific selectivity and high stability,the imprinted magnetic nanoparticles could easily reach the adsorption equilibrium and magnetic separation under an external magnetic field(4) To obtained a clean and safe materials for separation of Am (Ⅲ) and Eu (Ⅲ). We get three kinds gel beads, containing sodium alginate (SA)/Ca2+/multil-wall carbon nanotubes(MWNTs), (SA)/Ca2+/Fe3O4-SiO2and (SA)/Ca2+/MWNTs/Fe304-SiO2.In this study, MWNTs are individually dispersed in aqueous solution using SA with ultrasonic wave method. Their adsorption capacity for Eu3+was investigated The result showed that it has better adsorption for Eu(Ⅲ)at pH 6.更多还原