Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-(2-ethylhexyl) phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

Three New Zn(Ⅱ)/Cd(Ⅱ) Coordination Polymers Constructed with 2-Mercaptonicotinic Acid and 1,2-Di(4-pyridyl)ethylene: Syntheses and Structure Analysis

Three new Zn（Ⅱ）/Cd（Ⅱ） coordination polymers based on 2-mercaptonicotinic acid （H2mna） with 1,2-di（4-pyridyl）ethylene （dpe） introduced as a bridging ligand have been synthesized via hydrothermal method and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. As reported in this paper, [Zn2（dpe）0.5（mna）2] （1） can be classified as a two-dimensional layer structure in which the 1D chain composed of Zn（Ⅱ） and mna ligands is bridged by dpe ligands, while the complex named [Zn4（dpe）4（mna）4] （2） is a tetra-nuclear cluster compound. These two compounds are further extended to three-dimensional structures by hydrogen bonds along with C–H…π and π…π interactions. Compound 3 with general formular [Cd2（dpe）0.5（mna）2]·H2O belongs to a three-dimensional porous structure in which the 2D metal layers formed by the coordination of Cd（Ⅱ） and mna ligands are connected with the bridging of dpe ligands.

Effect of Temperature on the Reaction of 2-(N-acetylamine)-3-(3,5-di-<i>tert</i>-butyl-4-hydroxyphenyl)-propionic Acid with Oxygen in an Alkaline Condition

Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃?- 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.

Tb(III) Transport in Dispersion Supported Liquid Membrane System with D2EHPA as Carrier in Kerosene

The transport of Tb（III） in dispersion supported liquid membrane（DSLM） with polyvinylidene fluoride membrane（PVDF） as the support and dispersion solution including HCl solution as the stripping solution and di（2-ethylhexyl） phosphoric acid（D2EHPA） dissolved in kerosene as the membrane solution, has been studied. The effects of pH value, initial concentration of Tb（III） and different ionic strength in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on the transport of Tb（III） have also been investigated, respectively. As a result, the optimum transport conditions of Tb（III） were obtained, i.e., the concentration of HCl solution was 4.0 mol/L, the concentration of D2EHPA was 0.16 mol/L, the volume ratio of membrane solution to stripping solution was 30：30 in the dispersion phase and pH value was 4.5 in the feed phase. Ionic strength had no obvious effect on the transport of Tb（III）. Under the optimum conditions, the transport percentage of Tb（III） was up to 96.1% in a transport time of 35 min when the initial concentration of Tb（IIl） was 1.0× 10 -4 mol/L. The diffusion coefficient of Tb（III） in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.82×10 -8 m2/s and 5.61 um, respectively. The calculated results were in good agreement with the literature data.

Adsorption by Liquid-Liquid Extraction of Hg(II) from Aqueous Solutions Using the 2-Butyl-imidazolium Di-(2-ethylhexyl) Phosphate as Ionic Liquid

In this work, a novel room temperature ionic liquid (2-butyl-imidazolium di-(2-ethylhexyl) phosphate) ([C4mim] [D2EHPA]) was synthesized and tested as extractant in the mercury(II) liquid-liquid extraction. The effects of parameters such as aqueous to organic phase’s volume ratio, metal concentration IL concentration, pH levels, ionic strength, and temperature were reported. For the extraction of metal, [C4mim]3[R.HR]3[HgCl2]org and [C4mim]3[R.HR]3 [HgClOH]org species were formed where (H2R2) was D2EHPA. In the case of ionic strength, the results showed that the addition of sodium acetate at 0.302 mmol·L?1 to the aqueous phase strongly increased the mercury extraction yield (R = 100%). The extracted species were investigated by a calculation program using CHEAQS V. L20.1 inorder to determine the relation between the percentages of the extracted species and the extraction yield. The results showed that the extracted species in the best conditions were HgCl2 and HgClOH with respective percentages 80.66% and 18.29%.

Structure and aggregation behavior of cobalt-di(2-ethylhexy1)-phosphoric acid complexes in solvent extraction systems

Structure and aggregates formed from cobalt di(2 ethylhexyl)phosphoric acid (Co HDEHP) complexes in solvent extraction systems were investigated by FT IR, UV Vis and photon correlation spectroscopic (PCS) techniques. Results showed that the Co HDEHP complex displayed a dehydrated tetrahedral coordination structure of the chelate type in n heptane and the aggregates were rather small. The addition of co surfactant to the solvent produced a series of effect on the physicochemical nature of the molecular aggregates. In the presence of 2 octanol, a partially hydrated octahedral coordination structure was formed in equilibrium with the dehydrated tetrahedral structure for the Co HDEHP aggregates in the organic phase and the equilibrium was found to be affected by the ionic strength of the aqueous phase. Furthermore, the FT IR results showed that Co HDEHP complex in the presence of 2 octanol displayed a bridge coordination between the cobalt and the extractant molecules.

二-(2-乙基己基)磷酸与仲壬基苯氧基取代乙酸混合体系对稀土元素的萃取

考察了二-(2-乙基己基)磷酸(D2EHPA,H2A2)和仲壬基苯氧基取代乙酸(CA100,H2B2)混合体系在HCl介质中对15种镧系元素(除钷)及钇的萃取性能,计算了稀土元素间的分离系数,并比较了混合萃取体系与D2EHPA单独萃取体系对稀土元素的分离能力。研究了D2EHPA-CA100混合体系对镧的协同萃取机理,用斜率法和恒摩尔法探讨了萃取反应方程式,考察了酸度、萃取剂浓度及温度对萃取性能的影响。结果表明:D2EHPA-CA100混合体系对镧系元素的协同效应随原子序数的增加而减弱。在适当的萃取剂配比下,此混合体系对某些稀土元素的分离能力优于D2EHPA,可用于这些稀土元素的分离。D2EHPA-CA100混合体系协同萃取镧的萃合物组成为LaH5A6B2,反应为吸热反应。

二(2-乙基己基)磷酸络合萃取对氨基苯酚

二 (2 -乙基己基 )磷酸 (D2 EHPA)络合萃取对氨基苯酚 (PAP)。研究了稀释剂种类、溶液的初始 p H值等因素对稀溶液分配比 (D)的影响。溶液的初始 p H值 (p H2— 1 1 )对萃取结果影响较大 ,当初始 p H值在p Ka1 和 p Ka2 之间时 ,分配比出现峰值。稀释剂则主要是通过物理萃取实现。在同一浓度下 ,二 (2 -乙基己基 )磷酸的萃取能力随稀释剂的极性增大而提高 ,极性环境明显优于惰性稀释剂环境。红外光谱分析表明 ,络合萃取过程存在离子交换和离子缔合两种反应机制。

二(2-乙基己基)磷酸络合萃取邻氨基苯酚的研究

以二(2-乙基己基)磷酸(D2EHPA)为萃取剂,研究稀释剂种类、萃取剂浓度、溶液的初始pH值、溶液中甲(乙)醇等因素对邻氨基酚(OAP)稀溶液分配比(D)的影响.结果表明:溶液的初始pH值在7左右时,D有最大值;D值随二(2-乙基己基)磷酸浓度的增大而提高,且在极性环境要优于惰性环境;甲(乙)醇是影响萃取结果的主要因素.

P204萃取脱除铜精矿浸出液中铁

从含砷硫化铜精矿浸出液中萃取除铁是后续制备砷酸铜的一道工序,P204可从硫酸介质中选择性地萃取铁离子.实验结果表明,当有机相组成中P204为30%(-),相比1:1,pH≈1时,通过三级萃取,铁的萃取率达93%以上,铜和砷几乎不被萃取,萃余液中残铁含量降至9mg/L以下.

环保增塑剂环己烷-1,2-二甲酸二异辛酯的合成与应用

以环己烷-1,2-二甲酸酐(HHPA)与异辛醇为原料,甲烷磺酸为催化剂,合成了环保增塑剂环己烷-1,2-二甲酸二异辛酯(DEHCH),并与邻苯二甲酸二异辛酯(DEHP)的增塑性能进行了对比。经单因素实验得到最佳的合成工艺条件为:醇酐摩尔比为2.6∶1.0,催化剂用量为酸酐质量的0.25%,反应温度为170℃,反应时间2h,酯化率可达到97.89%。并用红外光谱、核磁共振、质谱表征了产物的分子结构,通过力学性能的对比可知,合成的DEHCH与DEHP有着相似的增塑性能,可以作为一种替代邻苯二甲酸酯类的增塑剂。

D2EHPA萃取稀土的有机相红外光谱及添加DMHPA的影响

本文研究了部分皂化的二（２－乙基己基）磷酸（Ｄ２ＥＨＰＡ）－正庚烷体系萃取稀土离子Ｙ３＋、Ｐｒ３＋、Ｎｄ３＋、Ｅｕ３＋后有机相的傅里叶变换红外光谱（ＦＴ－ＩＲ）。发现不同稀土离子与萃取剂的配位能力有差异，并且皂化度对萃取有机相中Ｐ＝Ｏ谱带的频率和吸收强度皆有影响。在Ｄ２ＥＨＰＡ中加入二（１－甲基庚基）磷酸（ＤＭＨＰＡ）。

二(2-乙基己基)磷酸萃取L-异亮氨酸的研究

以二(2-乙基己基)磷酸(D2EHPA)-正辛烷及D2EHPA-正辛醇萃取L-异亮氨酸为对象，研究了D2EHPA浓度、L-异亮氨酸初始浓度以及pH值对萃取平衡分配系数的影响。结果表明，在实验研究涉及的pH值范围内，分配系数先随pH的增加而增大，在3.5<pH<5区域，pH值对分配系数的影响较小。分配系数还随D2EHPA浓度的增加而增大。正辛醇加入有机相，萃取分配系数增大。D2EHPA与L-异亮氨酸生成萃合比为1∶1或2∶1的萃合物。证实了在D2EHPA萃取L-异亮氨酸的过程中存在着质子转移反应。建立的萃取平衡分配系数关联式的拟合精度是令人满意的。

皂化二-(2-乙基己基)磷酸微乳液及其萃取VO^(2+)的红外光谱研究

研究了利用氨水和ＮａＯＨ皂化Ｐ２０４煤油和Ｐ２０４仲辛醇煤油体系形成的微乳液萃取ＶＯ２＋的红外光谱变化规律。结果表明，两种皂化体系由于水化形成氢键，Ｐ＝Ｏ键的吸收频率均降低，萃取ＶＯ２＋后由于萃合物中两个Ｐ＝Ｏ键产生振动耦合吸收峰分裂为二。

皂化P_(204)/煤油微乳体系分离L-苯丙氨酸的研究

研究了P204-煤油-NaOH组成的微乳液膜配方及其稳定性。通过该液膜体系对L-苯丙氨酸水溶液进行提取实验,考察了P204的浓度、乳水比、外水相pH值、膜相重复使用次数、分离时间等对提取效率的影响。实验结果表明,微乳液膜不仅稳定性好,无明显溶胀和泄漏,分离速度快,而且分离效果好,可自动破乳,油相可重复多次使用,对L-苯丙氨酸的一次性提取率达88.25%。

二-(2-乙基己基)膦酸(P204)-熔融石蜡对金属铜的固液萃取研究

研究了用二-(2-乙基己基)膦酸(P204)-熔融石蜡在60℃对金属铜的固液萃取行为,探讨了酸度、萃取剂浓度、Cu2+浓度、稀释剂用量及搅拌时间等因素对金属铜萃取率的影响.用斜率法确定了萃取机理,测定并计算出了表观萃取平衡常数Kex和相关热力学参数.

聚丙烯中空纤维膜/二(2-乙基已基)膦酸体系萃取水溶液中铜离子的研究(英文)

研究了聚丙烯中空纤维膜接触萃取器中二（2-乙基已基）辟酸萃取金属铜离子的工艺条件以及溶剂夹带，分析了原料的PH值、两相流速、有机相初始铜离子浓度以及萃取膜面积对萃取效率的影响，结果表明，两相流速、萃取膜面积对萃取率基本无影响，而水溶液的pH值和有机相初始铜离子浓度的改变使萃取率在40％～99％之间变化。这主要是由于整个萃取过程的传质阻力主要来源于D2EHPA和Cu^2＋的界面配位络合反应阻力，当铜浓度比较高时，传质阻力或传质系数与铜浓度无关，其值基本不变；而当铜浓度降低时，传质阻力随着铜浓度的降低而增大，传质系数则随着铜浓度的降低而减小。

血尿酸和细胞间黏附分子1对2型糖尿病颈动脉内膜中层厚度的影响

目的探讨2型糖尿病合并颈动脉粥样硬化(CA)患者血尿酸、细胞间黏附分子1(ICAM-1)与颈动脉内膜中层厚度(IMT)的关系。方法选择2型糖尿病患者80例,根据诊断分为糖尿病合并颈动脉粥样硬化组(CA组)40例和单纯糖尿病组(对照组)40例,检测分析2组患者血尿酸、ICAM-1、收缩压、舒张压、空腹血糖、空腹胰岛素、糖化血红蛋白、餐后2 h血糖、餐后2 h胰岛素、HDL-C、LDL-C、TC、TG等糖、脂代谢指标及颈动脉IMT的水平差异。同时计算体重指数、胰岛素抵抗指数(HOMA-IR)。结果 CA组颈动脉IMT、血尿酸、ICAM-1、收缩压、体重指数、TG、TC、LDL-C、糖化血红蛋白、空腹血糖、餐后2 h血糖、空腹胰岛素、餐后2 h胰岛素、HOMA-IR均明显高于对照组(P<0.05,P<0.01)。血尿酸、ICAM-1与颈动脉IMT密切相关(P<0.01),作为CA的主要独立影响因素最先进入多元逐步回归方程。结论 2型糖尿病合并CA患者较无CA的糖尿病患者存在更明显的代谢紊乱、胰岛素抵抗、血管内皮功能障碍及炎性反应,早期联合检测血尿酸、ICAM-1有助于对糖尿病人群发生血管病变进行预测。

皂化P_(204)微乳体系萃取大豆蛋白的研究

研究了NaOH皂化P204/正辛烷微乳体系萃取大豆蛋白的机理和工艺,考察了大豆加入量、P204的浓度、NaOH的浓度、萃取时间、水相pH值及离子强度等对大豆蛋白萃取率的影响。实验结果表明,该微乳体系萃取大豆蛋白的优化工艺条件为:大豆粉与微乳液的质量体积比1∶10,P204在油相中浓度0.8 mol/L,NaOH的浓度1.25 mol/L,萃取时间15 min,外水相pH值5,萃取率可达88.48%。通过调节水相pH和离子强度可实现大豆蛋白的萃取和反萃取。