硫酸铵-碘化钾-溴化十六烷基吡啶体系浮选分离铅

研究了硫酸铵 碘化钾 溴化十六烷基吡啶体系浮选分离铅的行为及其与常见离子的分离条件。实验表明 :Pb2 + 与I- 形成的PbI2 -4能与溴化十六烷基吡啶 (CPB+ )形成浮于盐水相上层且不溶于水的三元缔合物 (PbI2 -4)·(CPB+ ) 2 。当碘化钾 (0 .5 0mol L)和CPB+ (1.0× 10 - 2 mol L)溶液的用量分别为 1.5 0mL和 2 .0 0mL时 ,Pb 可被完全浮选 ,控制pH =4 .0 ,该浮选体系能使Pb 与Zn 、Fe(Ⅲ )、Co 、Ni 、Mn 、Al(Ⅲ )等常见离子分离     

气相色谱-质谱法测定洗涤剂中的乙醇胺类化合物

建立了气相色谱-质谱(GC/MS)法测定洗涤剂中乙醇胺类化合物分析方法。选用DB-624 MS分析柱,对目标物乙醇胺(MEA)、二乙醇胺(DEA)、二甲基乙醇胺(DMEA)和三乙醇胺(TEA)进行测定。方法线性相关系数为0.995~0.997;RSD值均小于4.9%;回收率为87.8%~117.9%。该方法可用于洗涤剂中乙醇胺类有机物的定性检测。     

齐墩果酸-烷醇胺复合物的制备及性能

采用超声法制备齐墩果酸(OA)与烷醇胺(EAs)[单乙醇胺(MEA)、二乙醇胺(DEA)或三乙醇胺(TEA)]复合物,利用差示扫描量热、X射线衍射、红外光谱和拉曼光谱等技术手段对复合物进行了表征。 发现OA与EA之间无新的化学键形成,它们以分子间力结合形成复合物。 OA与EA复合物提高了OA的溶解度,为OA新型给药系统提供新思路和理论依据。     

新型乙醇胺型离子液体的合成与表征

由乙醇胺,二乙醇胺和三乙醇胺提供阳离子,由有机酸(甲酸,乙酸和丙酸)提供阴离子,合成了8种新型乙醇胺型离子液体,其结构经1H NMR,IR和元素分析表征.熔点、电导率等测定结果表明,他们均具有离子液体的特征.     

气相色谱法测定酰胺类表面活性剂及其制品中微量乙醇胺

建立了气相色谱法同时测定表面活性剂中单乙醇胺、二乙醇胺、三乙醇胺含量的方法。在试验条件下,单乙醇胺、二乙醇胺、三乙醇胺能很好地分离,采用保留时间定性、外标法定量。3种乙醇胺的质量浓度均在0.50~15.0g·L-1范围内与峰面积呈线性关系,相关系数分别为0.999 4,0.999 6,0.999 5,检出限(3S/N)为0.71,0.63,0.97mg·L-1。方法用于1比1型,1比1.5型烷醇酰胺和十二烷基苯磺酰三乙醇胺3种样品分析,加标回收率分别为95.2%~105%,96.4%~104%,96.4%~105%,测定值的相对标准偏差(n=5)在1.1%~2.2%之间。     

醇胺溶液吸收二氧化碳的实验研究

CO2的减排和有效利用受到人们的广泛关注.以二乙醇胺(DEA)、三乙醇胺(TEA)、N-甲基二乙醇胺(MDEA)溶液为对象,采用鼓泡吸收装置考察了醇胺的种类及浓度对CO2吸收速率和吸收容量的影响,研究了吸收前后溶液pH的变化,以及醇胺溶液再生后的情况.实验表明,醇胺溶液浓度增大有利于CO2的吸收,相同条件下DEA和TEA的吸收效果好于MDEA,醇胺溶液吸收CO2后pH由接近于11降至7左右,TEA的再生效果好于DEA.     

改进的两温区气相输运法合成碘化铅(PbI2)多晶

采用改进的两温区气相输运合成方法(MTVTM)合成PbI2多晶原料,简化了合成工艺,有效避免了合成安瓿爆炸。XRD分析结果表明:新方法合成的PbI2多晶原料纯度高,具有2H结构,P3ml空间群,晶格常数a=b=0.4560 nm,c=0.6979 nm。以此为原料,用垂直布里奇曼法(VBM)生长出电阻率达1013Ω·cm的PbI2单晶体。     

非抑制离子色谱法测定塑料食品接触材料中五种醇胺迁移量

建立了非抑制离子色谱法同时测定塑料食品接触材料中一乙醇胺(MEA)、二乙醇胺(DEA)、三乙醇胺(TEA)、三异丙醇胺(TIPA)、N,N-二乙基乙醇胺(DEAE)等5种醇胺类物质迁移量的方法。方法选用水、3%(m/V)乙酸、4%(V/V)乙酸、10%(V/V)乙醇、20%(V/V)乙醇、50%(V/V)乙醇、橄榄油、正己烷等8种物质作为食品模拟物,满足水性、酸性、醇类与脂类食品的模拟。在优化条件下,目标物检出限在0.03~2 mg/kg之间(S/N=3),加标回收率在84.1%~118.6%,精密度在0.92%~4.1%(n=6)之间。     

三乙醇胺对羟基亚乙基二膦酸镀铜液的影响研究

研究羟基亚乙基二膦酸(HEDPA)镀铜液中三乙醇胺(TEA)对铜还原和氧化过程的影响. 用Hull Cell测试阴极电流密度分布, 通过电位扫描、循环伏安和交流阻抗研究铜沉积的电化学行为, 通过镀液的吸光度测试和固体配合物的红外光谱分析推断配位化合物的形式. 结果表明: TEA的加入能够扩大HEDPA镀铜体系的阴极允许电流密度, 对铜电沉积有阻化作用, 促进铜阳极溶解, 并可抑制氢气的析出|随着溶液中TEA浓度增加, 在玻碳电极上发生的铜还原过程由电化学控制逐渐转变为扩散控制, 可获得结晶细小、表面平整的致密铜镀层. TEA的加入, 主要是在HEDPA镀铜体系中形成CuTEA(OH)₂配位化合物, 并吸附在电极表面而影响电化学反应.     

非水层状液晶的结构与稳定性 Ⅲ.三乙醇胺油酸盐层状液晶及其增溶特性

Friberg曾以等摩尔的三乙醇胺(TEA)与油酸(OLA)混合,生成了三乙醇胺油酸盐(TEA-OLA)非水层状液晶,并指出在TEA的作用下,大部分OLA去质子,生成了三乙醇胺油酸盐,组成层状液晶两亲双层,剩余的TEA、OLA作为溶剂存在于层状液晶的溶剂层中,本文报道以甲酰胺(FA)为溶剂时TEA-OLA与TEA-OLA/FA层状液晶的生成范围及其稳定性。     

OH radical reactions with ethanolamines: formation of reducing as well as oxidizing radicals

The reaction of OH radicals with ethanolamine, diethanolamine and triethanolamine was studied at pH values below and above the pK_a values of these compounds. The rate constants were found to be lower for the protonated amines than those for their neutral forms. The OH radical reaction led to the formation of both oxidizing as well as reducing species, as observed by their reactions with methyl viologen and ascorbic acid. The oxidizing species formed by OH radical reaction at the amine site was not found to react with the parent molecules and thereby no secondary yield of reducing species was obtained as in the case of glycine (except in the case of triethanolamine at pH 9.2).     

OH radical reactions with ethanolamines: formation of reducing as well as oxidizing radicals

OH radical reactions with ethanolamine, diethanolamine and triethanolamine were studied at pH values below and above the pK_a values of these compounds. The rate constants were found to be lower for the protonated amines than those for their neutral forms. The OH radical reaction led to the formation of both oxidizing, as well as reducing species, as observed by their reactions with methyl viologen and ascorbic acid. The oxidizing species formed by OH radical reaction at the amine site was not found to react with the parent molecules and thereby no secondary yield of reducing species was obtained, as in the case of glycine (except in the case of triethanolamine at pH 9.2).     

Solubility in ternary aqueous systems including calcium chlorate and diethanolamine (triethanolamine) at 25°C

Solubility in ternary aqueous systems including calcium chlorate and diethanolamine (triethanolamine) has been studied at 25°C. Solubility diagrams have been constructed. Solubility curves consist of three branches corresponding to the crystallization of calcium chlorate, diethanolamine (triethanolamine), and compound Ca(ClO₃)₂ · NH(C₂H₄OH)₂ or Ca(ClO₃)₂ · N(C₂H₄OH)₃. The compounds have been isolated and identified by chemical analysis, X-ray powder diffraction, and thermal analysis.     

Polymerization of methyl methacrylate with aminoalcohols and carbon tetrachloride initiated by charge-transfer mechanism

Polymerization of methylmethacrylate (MMA) with aminoalcohols, namely ethanolamine (EA), diethanolamine (DEA) and triethanolamine (TEA) in the presence of carbontetrachloride (CCl₄) has been investigated in the dimethylsulfoxide (DMSO) medium by employing a dilatometric technique. The rate of polymerization (R _p) has been evaluated under the conditions and > 1. The kinetic data reveal the possible participation of a charge-transfer complex in the polymerization reaction. In the absence of either CCl₄ or amine, no polymerization of MMA was observed under the present experimental conditions. The polymerization of MMA was inhibited by hydroquinone, indicating a free radical initiation.     

Oxidation of ethanolamines by sodium N‐bromobenzenesulfonamide in alkaline buffer medium: A kinetic and mechanistic study

The kinetics of oxidation of ethanolamines, monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA), by sodium N‐bromobenzenesulfonamide or bromamine‐B (BAB) in alkaline buffer medium (pH 8.7–12.2) has been studied at 40°C. The three reactions follow identical kinetics with first‐order in [oxidant] and fractional‐order each in [substrate] and [OH^?]. Under comparable experimental conditions, the rate of oxidation increases in the order: DEA > TEA > MEA. The added reaction product, benzenesulfonamide, retards the reaction rate. The addition of halide ions and the variation of ionic strength of the medium have no significant effect on the rate. The dielectric effect is negative. The solvent isotope effect k′(H₂O)/k′(D₂O) ≈ 0.92. Activation parameters for the composite reaction and for the rate‐limiting step were computed from the Eyring plots. Michaelis‐Menten type of kinetics is observed. The formation and decomposition constants of ethanolamine‐BAB complexes are evaluated. An isokinetic relationship is observed with β = 430 K indicating that enthalpy factors control the rate. For each substrate, a mechanism consistent with the kinetic data has been proposed. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 480–490, 2001     

Equilibrium and kinetic studies of electron transfer reactions involving quinolinium dichromate and aminoalcohols in aqueous acid media

Summary Oxidation of the aminoalcohols (AA) such as ethanolamine, diethanolamine and triethanolamine by quinolinium dichromate (QDC) yielded formaldehyde as the main product in aqueous H₂SO₄ and HClO₄ media. The reaction kinetics exhibited a first-order dependence on [QDC]. Plots of 1/k versus 1/[AA] indicated the formation of a QDC-A A adduct prior to the rate limiting step. The equilibrium constants, K, for the formation of QDC-AA adducts were evaluated by kinetic and spectroscopic (Ardon's) methods. The reaction was found to be catalysed by HClO₄ and H₂SO₄. The results were analysed in terms of various acidity function theories.     

Development of Diethanolamine Selective Production Process Using Shape-Selective Zeolite Catalyst

Ethanolamines are conventionally produced on an industrial scale exclusively by the reaction of ethylene oxide (EO) with an aqueous solution of ammonia. The reaction is a typical consecutive reaction with three steps [NH₃ → NH₂(CH₂OH) → NH(CH₂OH)₂ → N(CH₂OH)₃]; therefore, it is difficult to produce diethanolamine with high selectivity. We developed a catalytic process for selective diethanolamine production from EO and anhydrous ammonia using a ZSM-5 zeolite catalyst modified with rare earth elements. This highly active catalyst was able to recognize the difference at molecular level between diethanolamine and triethanolamine. We also succeeded in producing a binderless molded zeolite catalyst having a shape suitable for a fixed-bed reactor. This catalyst does not give problematic impurities due to undesirable reactions over binders. The catalyst deterioration was overcome by developing a regeneration process using high temperature and high-density ammonia gas as a rinse medium.     

Facile Synthesis of Dendritic Hydroxyl‐terminated Cyanuric Chloride Derivatives and Their Properties

Novel dendritic compounds G1.5(OH)₄ and G1.5(OH)₈ with peripheral hydroxyl were synthesized under mild conditions from cyanuric chloride, ethylene diamine, ethanolamine and diethanolamine. The products could be separated and purified through dispersion and precipitation in organic solvents with good yields (over 93.0%) and high purity (above 98.0%, HPLC). The structures of the products were characterized by IR, MS, ¹ H NMR and elementary analysis. G1.5(OH)₄ and G1.5(OH)₈ could be dissolved in polar solvents such as methanol, water and dimethylsulfoxide. TGA analysis showed that G1.5(OH)₄ and G1.5(OH)₈ had good thermo stability. The aqueous solutions of G1.5(OH)₄ and G1.5(OH)₈ exhibited low surface tension.     

In situ Investigations of Interfacial Degradation and Ion Migration at CH3NH3PbI3 Perovskite/Ag Interfaces

Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells. Here, we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH₃NH₃PbI₃ perovskite layer and Ag electrode. Using in situ photoemission spectroscopy measurements, we found that the Ag electrode could induce the degradation of perovskite layers, leading to the formation of PbI₂ and AgI species and the reduction of Pb²⁺ ions to metallic Pb species at the interface. The unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH₃NH₃PbI₃ subsurface to Ag electrode. Moreover, the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH₃NH₃PbI₃/Ag interfaces, which may further facilitate iodide ion di usion, resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.     

Synthesis and characterization of cobalt(II) complexes with triethanolamine and succinate and/or nitrate anions

Three Co(II) complexes of triethanolamine (TEA) namely [Co(N(CH₂CH₂OH)₃)₂](NO₃)₂ (1), [Co(N(CH₂CH₂OH)₃)₂](OOC(CH₂)₂COO) (2) and [Co₂(N(CH₂CH₂OH)₃)₂(NO₃)₂(OOC(CH₂)₂COO)] (3) were synthesized and characterized by physicochemical and spectroscopic methods. The first two complexes are cationic and are formed by Co²⁺ cations coordinated by two TEA ligands plus nitrate or succinate anions, respectively. The equilibrium geometries of the [Co(TEA)₂]²⁺ cations have been optimized at the B3LYP/cc-pVDZ level. Complex 3 is a product of the reaction between cationic complexes 1 and 2.