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《分离科学与技术》2012,47(10):1541-1554
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. 相似文献
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Extraction behavior of strontium from nitric acid medium with N,N’-dimethyl-N,N’-dioctyldiglcolamide
Strontium-90 (90Sr), one of the most significant fission products carried into high-level waste (HLW), should preferably be separated from HLW. In this investigation, the extraction of Sr2+ was carried out using N,N’-dimethyl-N,N’-dioctyldiglcolamide (DMDODGA) in 40/60 (V/V)% 1-octanol/kerosene or ionic liquid (IL) [C6mim][Tf2N]. The composition of the extracted complex between DMDODGA and HNO3 depends on the aqueous HNO3 concentration. The distribution ratio of Sr2+ (DSr) is influenced by the initial concentration of HNO3 and strontium in the aqueous phase, the concentration of DMDODGA, and temperature. The stoichiometry of Sr2+ and DMDODGA in the extracted complex is 1:3. DSr in the IL is two orders of magnitude higher than that in 40/60 (V/V)% 1-octanol/kerosene at lower acidity. 相似文献
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Kathryn M. L. Taylor-Pashow Fernando F. Fondeur Thomas L. White David P. DiPrete 《分离科学与技术》2015,50(18):2866-2872
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. 相似文献
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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. 相似文献
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Larissa Klaß Andreas Wilden Fabian Kreft Christoph Wagner Andreas Geist Petra J. Panak 《溶剂提取与离子交换》2013,31(5):297-312
ABSTRACTN,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] 相似文献
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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。 相似文献
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N,N’-双月桂酰基乙二胺二乙酸钠合成方法的改进 总被引:1,自引:0,他引:1
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。 相似文献
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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。 相似文献
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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) 总被引:2,自引:0,他引:2
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%。 相似文献
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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。 相似文献
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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。 相似文献
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