铀的萃取剂——二(苯基亚磺酰)烷烃的合成

双亚砜;硫醚;铀的萃取剂——二(苯基亚磺酰)烷烃的合成     

铀酰萃取剂双亚砜的合成及其微胶囊萃取铀性能的研究

铀是一种非常重要的能源物质 ,现在国际上一般使用磷酸三丁酯 (ＴＢＰ)作为铀的萃取剂提取及回收铀。ＴＢＰ对铀有较强的萃取能力 ,但它耐辐照能力较差 ,有关双亚砜的报道仅局限于ｎ =1 ,2 [1,2 ] 。本文以硝酸为氧化剂 ,采用硫醚氧化法 ,合成了四个新的双亚砜类化合物ＰｈＳＯ(ＣＨ2 ) ｎＳＯＰｈ(ｎ分别为 2、3、4、6) ,并经元素分析、核磁共振对其结构进行了表征。为避免萃取过程中乳化或三相的出现 ,采用界面缩聚法[3 ] 以高分子材料包覆ＴＢＰ和自制的双亚砜类化合物 (ｎ =2 ,4,6) ,制成微胶囊 ,对其在酸性水溶液 (ｐＨ =1～1 .5 )中萃…     

钇的双亚砜配合物的合成及表征

具有双齿配位基团的双亚砜作为金属离子的萃取剂已引起人们的注意,双亚砜的过渡金属和镧系元素的配合物已有较多研究,而钇的双亚砜配合物却报导甚少。为扩展双亚砜对金属离子的配位作用的研究,和为双亚砜作为钇与其它稀土元素分离的萃取剂提供基础数据,本文合成了钇的高氯酸盐,硝酸盐和氯化物与高、低熔点的双(正—辛基亚砜)乙烷(α、β—BOSE)和双(苯基亚砜)乙烷(αβ—BPhSE)的十二个配合物,并对其性质进行了研究。     

亚砜萃取有机酸机理的研究

用双对数法测出酒石酸石油亚砜萃合物的在观结构,并用红外光谱证明酸与亚砜以氢键相连。利用场解吸质谱可直接观察到有机酸亚砜萃合物的分子离子和准分子离子,比较多种有机酸纸层析的R_f值发现,亚砜萃取有机酸的机理中空腔效应起着重要作用。     

四丁基脲从硝酸介质中萃取铀(VI)行为的研究

与常用的铀萃取剂磷酸三丁酯(TBP)相比较,酰胺的理化性质类似于TBP,其主要优点是：降解产物一般不影响裂片元素的去污,产物无固体生成,属于“可完全燃烧”萃取剂,可大大减少放射性废物量。本文用非光气法合成了N,N,N’,N’-正四丁基脲(以下简称TBU),并以无毒性的石油醚作稀释剂,其对铀的萃取规律类似于TBP,萃取能力略低于TBP,在各实验条件下均不出现三相,铀的溶剂化数为2。     

液相色谱-质谱联用分析土壤中的双(2-羟乙基)亚砜

建立了液相色谱 质谱联用技术测定土壤中双(2 羟乙基)亚砜的方法。对影响检测灵敏度的流动相组成、流速、探头温度等因素进行了优化,在优化实验条件下,方法线性范围在0.05～20mg L之间,最低检测质量浓度为0.025mg L(S N>3),对比了3种萃取剂对4种土壤中的双(2 羟乙基)亚砜的萃取率,结果表明,用水作萃取剂的萃取效果最佳,回收率在92%以上,RSD均小于4%。     

N－正辛基己内酰胺从硝酸介质中萃取铀（Ⅵ）的动力学研究

采用上升单液滴往研究了Ｎ－正辛基己内酰胺从硝酸介质中萃取铀（Ⅵ）的动力学。得出Ｕ（Ⅵ）的萃取速率与水相中铀浓度的１次方成正比，与温度（１０～４５℃）无关；萃合物向有机相的扩散为萃取过程的速控步骤。     

N—正辛基己内酰胺从硝酸介质中萃取铀（Ⅵ）的动力学研究

采用上升单液滴法研究了Ｎ－正辛基己内酰胺从硝酸介质中萃取铀（Ⅵ）的动力学，得出Ｕ（Ⅵ）的萃取速率与水相中铀浓度的１次方成正比，与温度（１０－４５℃）无关；萃合物向有机相的扩散为萃取过程的速控步骤。     

DEHSO萃取铊(Ⅲ)及其机理的研究

二(2-乙基已基)亚砜(DEHSO)是带支链的烷基亚砜,其溶解性能优于直链烷基亚砜,对铊(Ⅲ)的萃取化学尚来见报道。 本文研究了DEHSO-煤油溶液在盐酸介质中对铊(Ⅲ)的萃取行为。实验结果表明,该萃取反应速率快,萃取率随酸度增大而增大,随Cl~-离子浓度增大而降低;温度升高致使分配比下降,由logD与1/T×10~3对画图得斜率为1.95的直线,据此求得萃取反应的焓变     

铀(Ⅵ)的二溴水杨醛缩二胺类双希夫碱及溶剂三元配合物的合成和表征

铀（Ⅵ）的二溴水杨醛缩二胺类双希夫碱及溶剂三元配合物的合成和表征郑庚修＊毕彩丰张家祥王秋芬张广友（山东建材学院应用化学系，济南２５００２２）关键词：硝酸铀双希夫碱三元配合物关于铀与希夫碱的配合物的结构、萃取等研究已有报道。结构研究发现：铀（Ⅵ）盐可以...     

Heterogeneous catalytic aerobic oxidation behavior of Co–Na heterodinuclear polymeric complex of Salen-crown ether

A new kind of Co–Na heterodinuclear polymer complex based on Salen Schiff base and crown ether has been successfully prepared by condensation polymerization. Its catalytic behavior for aerobic oxidation of cyclohexene, alkylbenzenes and linear aliphatic olefins was studied in the absence of any solvents or reducing agents under mild conditions. The oxidation of cyclohexene catalyzed by the above catalyst proved to be a simple and efficient method for obtaining 2-cyclohexen-1-one (CO) and 2-cyclohexen-ol (OH) in a high selectivity. Kinetics of the oxidation was also investigated. The results showed that the aerobic oxidation of cyclohexene catalyzed by Salen-crown ether heterodinuclear polymer complex follows a radical chain aerobic oxidation mechanism. This oxidation system is also efficient in the oxidation of alkylbenzenes and linear aliphatic olefins, which afforded corresponding benzylic oxidation products and epoxides, respectively.     

Pt及其修饰电极上乙醇吸附和氧化的CV和EQCM研究

运用电化学循环伏安和石英晶体微天平研究了乙醇在Pt电极和以Sb,S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程。结果表明乙醇的氧化与电极表面氧物种有着极其密切的关系。Pt电极表面Sb吸附原子能在较低的电位下吸附氧,可显著提高乙醇电催化氧化活性。相反,Pt电极表面S吸附原子的氧化会消耗表面氧物种,抑制了乙醇的电氧化。本文从表面质量变化提供了吸附原子电催化作用的新数据。     

烷基对蒽衍生物在水-乙腈中用硝酸铈铵氧化机理的影响

在水-乙腈混合溶剂中用(NH~4)~2Ce(NO~3)~6氧化烷基蒽. 甲基, 乙基和环丙基蒽经历氧化-水解-氧化-水解-消除-氧化-去质子历程, 得到蒽环氧化产物, 消除烷基(或氢原子)的可能顺序是:H＞CH~3＞C~2H~5. 当蒽环的1,9-位连着1,2-亚乙基桥时, 却经由氧化-去质子-氧化水解-氧化(或消除)历程, 得到侧链氧化产物. 烷基的本质对多核芳烃的氧化机理有显著的影响.     

A study of the oxidation of titanium hydride powder by measurements of its electrical resistance

The oxidation of titanium hydride powder by air oxygen and the influence of oxidation conditions on the degree of oxidation of hydride particles, specific gas content in the powder, and kinetics of its thermal decomposition were studied. The resistometry method was used to determine the effective activation energy of oxidation of titanium hydride by air oxygen. The content of the surface nonconducting phase formed by titanium oxide and oxohydride films under various oxidation conditions was estimated.     

Pt及其修饰电极上甲醇吸附和氧化的CV和EQCM研究

运用电化学循环伏安和石英晶体微天平 (EQCM )研究了 0 .1mol·L- 1H2 SO4 溶液中甲醇在Pt电极和以Sb ,S不可逆吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程 .结果表明甲醇的氧化与电极表面氧物种有着极其密切的关系 .Pt电极表面Sb吸附原子能在较低的电位下吸附氧 ,可显著提高甲醇电催化氧化活性 .与Pt电极相比较 ,Sb吸附原子修饰的Pt电极使甲醇氧化的峰电位负移了 0 .13V .相反 ,Pt电极表面S吸附原子的氧化会消耗表面氧物种 ,抑制了甲醇的电氧化 .本文从表面质量变化提供了吸附原子电催化作用的新数据     

基于三维荧光光谱的乳制品脂氧化判别方法

为快速、无损判别乳制品脂氧化程度,提出了利用乳制品三维荧光光谱的氧化水平进行判别的方法。该方法用平行因子分析对荧光矩阵进行分解,用载荷向量组确定脂氧化过程中的光敏成分,用不同成分得分向量对样本进行聚类,并建立了不同氧化水平样本的偏最小二乘判别模型。实验采集不同存储环境下氧化程度各异的酸奶样本,找出了核黄素等荧光团在脂氧化过程中的变化规律,选取得分向量建立偏最小二乘判别模型对不同存储阶段氧化程度各异的样本判别分类,其特异度和灵敏度达88.9%以上,验证了该法对评判乳制品脂氧化水平的有效性。     

The kinetics of oxidation of bilirubin and ascorbic acid in solution

The results of a comparative study of the oxidation of bilirubin, ascorbic acid, and their mixture in aqueous solutions under the action of air oxygen and hydrogen peroxide are presented. The observed and true rate constants for the oxidation reactions were determined. It was shown that the oxidation of tetrapyrrole pigment occurred under these conditions bypassing the stage of biliverdin formation to monopyrrole products. Simultaneous oxidation of bilirubin and ascorbic acid was shown to be accompanied by the inhibition of ascorbic acid oxidation by bilirubin, whereas ascorbic acid itself activated the oxidation of bilirubin.     

The Electro‐Oxidation of Formaldehyde at a Boron‐Doped Diamond Electrode

Abstract

The characteristics of the boron‐doped diamond (BDD) electrode in this work were studied by atomic force microscope (AFM), scanning electron microscopy, and Raman spectroscopy. The electro‐oxidation of formaldehyde at the BDD electrode in 0.5 M K₂SO₄ with different pH was studied by cyclic voltammetry and amperometry. There is no significant oxidation peak of formaldehyde in acidic solution because the oxidation of formaldehyde is at the potential range of water discharge. However, in neutral solution, there is a well‐defined oxidation peak at about +2.2 V vs. Ag/AgCl. The relation between the response current and formaldehyde concentration is linear behavior at the concentration range from 50 to 600 µM. Besides, in neutral solution, the oxidation of formaldehyde is dominated by indirect oxidation at lower formaldehyde concentration, and it is dominated by direct oxidation at higher concentration. Finally, in alkaline solution, the oxidation of formaldehyde is dominated by indirect oxidation caused by a powerful oxidant and is related to the ratio of the amounts of formaldehyde and OH molecules at the BDD electrode surface.     

单分散的还原态和中间氧化态聚苯胺齐聚物的合成与紫外光谱研究

提出了一条合成苯胺齐聚物的新路线:由高氧化态的苯胺四聚体与二苯胺或N-苯基-1,4-对苯二胺反应合成苯基封端的苯胺五聚体和六聚体,用红外、质谱、核磁共振、基底辅助激光解吸质谱(MALDI-MS)进行了表征.提出一条可能的机理,即高氧化态的苯胺四聚体与二苯胺或N-苯基-1,4-对苯二胺在酸性溶液中混合时,四聚体、二苯胺和N-苯基-1,4-对苯二胺的分子中均形成阳离子自由基,四聚体的阳离子自由基与后二者的阳离子自由基耦合形成苯胺五聚体和六聚体.还原态的苯胺齐聚物氧化成中间氧化态的苯胺齐聚物,使用硫酸铵和六水和三氯化铁等氧化剂能打断苯胺五聚体和六聚体的分子链.实验发现,氧化银是将还原态苯胺齐聚物氧化成中间氧化态的齐聚物的最好的氧化剂.用紫外可见光谱对中间氧化态的五聚体和六聚体进行了研究,对其分子中醌环的数目进行了讨论.     

Thermo- and photooxidation of polyisobutylene. I. Evolutions at temperatures above 50°C

Polyisobutylene films (PIB) were submitted to a thermal oxidation at 100°C and to a photooxidation by exposure to long-wavelength radiations (λ ≥ 300 nm) at 60°C. The modifications of the chemical structure resulting from the oxidation were determined by FT-IR analysis of the polymer films, coupled to chemical treatments that converted specifically the oxidation products. Dissolution of oxidized samples permitted analysis of the polymer by ¹³C- and ¹H-NMR. The structure of the volatile products was determined by mass spectroscopy analysis of the gas phase. Identification of the numerous products formed permitted the proposal of a scheme that accounts for the oxidation of PIB. When the irradiations are carried out at a temperature above 50°C, the depolymerization is favored and the mechanism involves two main routes of oxidation. A direct oxidation starts with the oxidation of radicals obtained by homolysis of the C C bonds on the main chain, and an induced oxidation involves hydrogen abstraction on the methylene and methyl groups by radicals formed by the direct oxidation of the polymer. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1689–1701, 1997