Non-Dispersive Solvent Extraction of Neodymium using N,N,N’,N’-Tetraoctyl Diglycolamide (TODGA)

Hollow fiber contactor was used to study non-dispersive extraction (NDSX) of Nd³⁺ ions from aqueous solutions. N,N,N′,N′-tetraoctyl diglycolamide (TODGA) diluted with n-dodecane was used as the organic phase with di-n-hexyl octanamide (DHOA) as the phase modifier. The role of cations (H⁺/Na⁺) on the transport of Nd³⁺ ions has been investigated for this system. It was observed that H⁺ ion has a significant role to play in the Nd³⁺/TODGA complexation reaction. A mathematical model has also been developed to simulate the NDSX process in a hollow fiber contactor. A comparison has also been made between extraction profiles from the NDSX process and the hollow fiber supported liquid membrane (HFSLM) process. It was observed that NDSX gave comparatively faster rates of extraction in the presence of H⁺ ions but slower in the absence of H⁺ ions.     

Determination of N,N’, N’’-tris(3,7-dimethyloctyl)guanidine (TiDG) in Cesium Extraction Solvent

Several analytical methods were evaluated for determining the concentration of N,N’,N”-tris(3,7-dimethyloctyl)guanidine (TiDG) in a cesium extraction solvent. Of the methods evaluated, non-aqueous titration and ¹H NMR were shown to be successful at quantifying the amount of TiDG present in both a pure solvent extraction system, and a blended system containing an additional base, trioctylamine.     

N,N,N’,N’-四丁基-3-氧戊二酰胺萃取铁(Ⅲ)的研究

在两种稀释剂体系中研究了N,N,N’,N’-四丁基-3-氧戊二酰胺(TBOPDA)从盐酸介质中萃取铁离子的性能和反应机理。考察了水相盐酸浓度、萃取剂浓度及温度对其萃取性能的影响。实验结果表明分配比随盐酸浓度的增加而增加;随萃取剂浓度的增加而增大;萃取过程为放热过程,升高温度不利于萃取。     

Electrospin of polysulfone in N,N’-dimethyl acetamide solutions

Nanofibers of polysulfone (PSU) were prepared by electro-spinning from 10∼20 wt.% PSU solutions in N,N’-dimethyl acetamide (DMAc) mixed with 0.0∼0.1 wt.% LiCl. With increasing PSU concentration, the morphology of fibers electrospun were bead, mixture of bead-fiber and fiber, and smooth fibers when PSU concentration was 10, 12–15, and 18–20 wt.%, respectively. The bead sizes decreased and fiber diameters increased as PSU concentration was increased. The fiber diameter decreased with increases of the LiCl concentration and the distance from spinneret to collection plate. The fiber diameter also decreased with decreasing solution feeding rate. The fiber diameter distribution electrospun from 20 wt.% PSU solutions was much broader than those electrospun from 18 wt.% PSU solution. For 18 wt.% PSU solution, the average fiber diameter (AFD) decreased when the applied voltage V was increased from 7 to 12 kV. However, for 20 wt.% PSU solutions, the AFD increased when V was increased from 7 to 12 kV. The different morphology of fibers electrospun from 18 and 20 wt.% PSU solutions was attributed to the much higher viscosity of 20 wt.% PSU solution than 18 wt.% PSU solution.     

Insight into nitric acid extraction and aggregation of N,N, N’, N’-Tetraoctyl diglycolamide (TODGA) in organic solutions by molecular dynamics simulation

The molecular dynamics (MD) simulation of TODGA in n-dodecane shows formation of nanostructures of TODGA aggregates with nitric acid and water. These aggregates are dispersed in dodecane phase or form well defined reverse micelles grown sufficient in size depending on the acid concentration. With increasing nitric acid concentration, aggregation number of TODGA in reverse micelles also increases which, however, is independent of TODGA concentration. Aggregation number rises from 2 to 8 in presence of 0–3.5 M nitric acid in corresponding aqueous phase. The formation of the aggregates explains remarkable acid co-extraction from aqueous phase to organic dodecane phase by TODGA.     

Evaluation of the Hydrophilic Complexant N,N,N’,N’-tetraethyldiglycolamide (TEDGA) and its Methyl-substituted Analogues in the Selective Am(III) Separation

ABSTRACT

N,N,N’,N’-tetraethyldiglycolamide (TEDGA) is used in the French EXAm (extraction of americium) process to separate Am(III) from Cm(III) and Ln(III). In this study, the complexation behavior of TEDGA towards actinides(III) and lanthanides(III) was compared to its methyl-substituted derivatives Me-TEDGA and Me₂-TEDGA under experimental conditions applying to the EXAm process. Using the EXAm solvent, 0.6 mol/L N,N’-dimethyl-N,N’-dioctyl-hexylethoxymalonamide (DMDOHEMA) and 0.45 mol/L bis(2-ethylhexyl)-phosphoric acid (HDEHP), An(III) and Ln(III) distribution ratios increase in the order TEDGA < Me-TEDGA < Me₂-TEDGA. This is explained by differences in the strength of complexation in the aqueous phase: Conditional stability constants for the formation of [Cm(DGA)_x]³⁺ complexes decrease in the order TEDGA > Me-TEDGA > Me₂-TEDGA, as shown by time-resolved laser fluorescence spectroscopy (TRLFS). TRLFS measurements verified the exclusive existence of [Cm(DGA)₃]³⁺ complexes in the aqueous phase. Both the homoleptic [Cm(DMDOHEMA)_n]³⁺ and the heteroleptic [Cm(DGA)_x(DMDOHEMA)_y]³⁺ complexes were detected in the organic phase, as postulated in the literature.^[14]     

N,N,N’,N’-四甲基-N”-苯基胍的合成及其催化CO2法合成二甘醇双烯丙基碳酸酯

采用三氯氧磷法合成了一种新型五取代有机胍 N,N,N′,N′-四甲基-N″-苯基胍（PhTMG）,利用IR、¹H NMR、ESI-MS等方法对其结构进行了表征。考察了PhTMG对以二甘醇（DEG）、氯丙烯（ACH）和CO₂为原料合成二甘醇双烯丙基碳酸酯（ADC）反应的催化性能,ADC的最高收率为95.3％。采用GC-MS、XRD、IR等分析手段结合实验验证对ADC合成反应机理进行了研究,推测出该反应分4步进行：第1步,CO₂、DEG和Na₂CO₃反应生成二甘醇单碳酸钠盐;第2步,二甘醇单碳酸钠盐和ACH反应生成二甘醇单烯丙基碳酸酯（DGAC）;第3步,DGAC、CO₂和Na₂CO₃反应生成二甘醇单烯丙基碳酸酯单碳酸钠盐;第4步,二甘醇单烯丙基碳酸酯单碳酸钠盐与ACH反应生成目的产物ADC。并推测了反应体系中的主要副反应。     

N,N’-二甲基乙酰胺工业废水的降解方法研究进展

N,N’-二甲基乙酰胺是工业领域广泛使用的溶剂,对其废水进行降解排放,对环保有着重要意义,对现阶段用于N,N’-二甲基乙酰胺废水降解的原理、应用等进行了简单介绍。     

N,N’-双月桂酰基乙二胺二乙酸钠合成方法的改进

对表面活性剂N,N’-双月桂酰基乙二胺二乙酸钠的合成方法进行了改进。以月桂酸、乙二胺和氯乙酸为原料制得N,N’-双月桂酰基乙二胺二乙酸钠。考察了反应温度、反应时间、原料配比对中间体合成的影响。结果表明,N,N’-双月桂酰基乙二胺(中间体Ⅰ)的最佳合成条件是:n(月桂酰氯)∶n(乙二胺)=3.5∶1,反应温度70℃,反应时间1 h,产率为96.94%;N,N’-双月桂酰基乙二胺二乙酸(中间体Ⅱ)的最佳合成条件是:n(氯乙酸)∶n(中间体Ⅰ)=3∶1,反应温度65℃,反应时间12 h,产物产率为53.38%。产物结构用红外光谱、元素分析等方法进行了表征。     

酸性离子液体催化合成N,N’-亚甲基双丙烯酰胺

以N-甲基咪唑、2-氯乙基苯、硫酸氢钾合成1-甲基-3-[α-甲基-(4-磺酸苄基)]咪唑硫酸氢盐酸性离子液体,考察了酸性离子液体在甲醛和丙烯腈反应合成N,N’-亚甲基双丙烯酰胺(MBA)中的催化性能。结果表明,合成MBA的最佳反应条件为∶n(甲醛)∶n(丙烯腈)=1.2∶1.0,酸性离子液体用量为丙烯腈质量的8.0%,反应温度70℃,反应时间2 h。在该条件下MBA的收率>92%,纯度为98%以上,且反应结束后,产物易于分离,酸性离子液体可循环使用5次以上。     

含磷的金属螯合剂—N,N,N‘,N’—烃基二氨基四亚甲基膦酸的合成研究（Ⅲ）

ＥＤＴＭＰ［Ｎ，Ｎ，Ｎ＇，Ｎ＇－乙二氨基四亚甲基膦酸］和ＨＤＴＰ［Ｎ，Ｎ，Ｎ＇，Ｎ＇－１，６－己二氨基四亚甲基膦酸］是一类重要的金属螯合剂。以甲醛、三氯化磷、乙二胺和己二胺为原料合成了ＥＤＴＭＰ和ＨＤＴＰ，经柱色谱分离，产率在５６％以上，含量大于９８％。     

N,N’——二羧甲基联苯胺对贵金属反相纸层析的研究

分别以 N,N’——二羧甲基联苯胺的乙醇——苯溶液和氯仿溶液为固定相 ,以不同浓度的盐酸和高氯酸为展开剂 ,用反相纸层析法研究了 N,N’——二羧甲基联苯胺对8种贵金属的萃取行为。结果表明 :在乙醇——苯混合溶剂中固定相对贵金属的萃取能力比在氯仿溶剂中强。在高氯酸展开剂中对 Au3 、Ru3 、Rh3 的萃取能力较强 ;在盐酸展开剂中对Pd2 、Pt4 、Os4 、Ir4 、Ag 的萃取能力较强。     

丙烯基硫脲与N,N’-亚甲基双丙烯酰胺的共聚反应研究

利用微波辐射方法对丙烯基硫脲与N,N’-亚甲基双丙烯酰胺的共聚反应进行研究,同时与相应的热聚合进行比较,证实了丙烯基硫脲与N,N’-亚甲基双丙烯酰胺在不同的反应体系（溶液聚合和固相聚合）及不同的聚合方式（微波辐射聚合和加热聚合）,其反应活性不同。用气相色谱法测得在微波团相有引发剂时的竞聚率分别为丙烯基硫脲的r1＝0．9804,N,N’-亚甲基双丙烯酰胺的r2＝1.0027。在无引发剂存在时竞聚率分别为r1＝1.1875,r2＝1．1251。而相应的加热有引发剂存在时的共聚竞聚率分别为r1＝0.6320,r2＝0．2354。微波辐射在引发剂存在下的溶液聚合的竞聚率分别r1＝0.2750,r2＝0.6636。所得的聚合物可作为金属离子捕捉剂。     

N,N’-二硫代二吗啉的无水制备工艺研究

以吗啉和一氯化硫为原料,以固体氢氧化钠为缚酸剂合成了N,N’-二硫代二吗啉(DTDM),考察了反应条件和重结晶条件对产物收率的影响。结果表明,较佳的合成工艺条件为:n(吗啉)∶n(S2Cl2)∶n(NaOH)=2∶1∶2,反应温度30~40℃,反应时间8 h,粗产品收率可达93%;较佳的重结晶工艺条件为:溶剂乙酸乙酯,m(溶剂)∶m(产品)=4∶1,结晶温度0~5℃,重结晶收率可达93%,DTDM总收率可达86%以上,采用FTIR与1H NMR对产物结构进行了表征。     

N,N’-1,4-二对甲苯磺酰高哌嗪的合成

以甲醇钠为催化剂合成出N,N’-1,4-二对甲苯磺酰高哌嗪,考察了原料的物质的量比、反应时间、溶剂用量和相转移催化剂用量4种因素对反应收率的影响,较佳工艺条件为:N,N’-1,4-二对甲苯磺酰乙二胺0.02 mol时,N,N’-二对甲苯磺酰乙二胺和1,3-二溴丙烷的投料物质的量比1∶1.25,反应时间13 h,溶剂二甲基甲酰胺用量60 mL,苄基三乙基溴化铵用量0.6 g,总收率达65.65%。