Electrochemical Decomposition of Phenylhydrazine on a Fibrous Carbon Electrode

Oxidation of phenylhydrazine by atmospheric oxygen in aqueous solution, its catalytic breakdown in the presence of Aktilen A carbon fiber, and electrochemical decomposition on a polarized carbon fiber were studied. Formation of various organic products of phenylhydrazine breakdown, remaining in solution after oxidation with air and catalytic decomposition on a carbon fiber, was studied by spectroscopy and chromatography. Feasibility of electrochemical decomposition on a carbon fiber for wastewater treatment to remove hydrazine derivatives was examined.     

Phase Separation of Polyethylene Glycol/Salt Aqueous Two-Phase Systems

Abstract

Salt in polyethylene glycol (PEG)/salt aqueous two-phase systems was excluded by PEG and concentrated in the solvent volume available for dissolution of salt (PEG-free solvent). The concentration of salt in the PEG-free solvent of the PEG-rich phase was the same as that at the critical point regardless of the compositions of the PEG/salt two-phase systems. This explained that the phase separation of PEG/salt two-phase systems occurs when the concentration of salt in the PEG-free solvent reaches its solubility limit. The concentration of salt required in the PEG-free solvent for the phase separation was lower with higher molecular weight of PEG. The solubility of salt in the PEG-free solvent decreased with increases in the molal surface tension increment of salt. The solubility limit of salt in the PEG-free solvent was 0.93 M for ammonium sulfate, 0.77 M for potassium phosphate, 0.75 M for sodium tartrate, 0.67 M for sodium phosphate, and 0.53 M for potassium citrate.     

熔盐电解法制备镨钕钆合金的研究

本工艺采用熔融氟化锂-氟化镨钕-氟化钆熔盐三元体系为电解质,通过电解氧化钆与氧化镨钕混合物的方法,制备了成分稳定的镨钕钆合金,同时就电解质组元、温度、阴极电流密度、加料速度对电解过程的影响进行了试验研究。结果表明:在试验条件下可以生产钆含量(10~15)%±0.5%(质量分数)的镨钕钆合金,金属直收率大于98%,电流效率大于78%;产品含碳小于0.05%,含铁小于0.3%,含Ca,W均小于0.01%,同时具有成本低、工艺稳定、产品质量好等优点。     

离子液体双水相溶剂浮选法分离/富集桑黄黄酮类成分

将亲水性离子液体氯化-1-丁基-3-甲基咪唑([C4mim]Cl)和K2HPO4形成的双水相体系与溶剂浮选结合,建立了分离/富集桑黄中总黄酮类成分的方法。考察了分相盐的种类和用量、样品量、溶液pH值、浮选时间和氮气流速对浮选效果的影响,并与双水相萃取进行比较。当浮选分相盐K2HPO4的质量浓度为50%、溶液pH=9.53、离子液体的用量为3 mL、浮选时间为50 min、氮气流速为30 mL/min时,浮选效率最佳,达到85.31%,富集倍数为8.59。离子液体双水相溶剂浮选法浮选效率高,富集倍数大,为中草药有效成分分离/富集提供了新方法。     

Separation of Multicomponent Mixture of Naphthalene Derivatives by Reversed-Phase High-Performance Liquid Chromatography

Separation of a mixture of naphthalene derivatives by reversed-phase high-performance liquid chromatography with UV detection was studied. Chromatographic characteristics were calculated for nine compounds, including naphthalene.     

Universal Separation Potential for Multicomponent Mixtures: Reasons for Its Absence

Russian Journal of Physical Chemistry A - The topic of this study is discussion aimed at developing a unified viewpoint on the problem of separation potential and separating power in the theory of...     

铝盐配位分离氟碳铈矿酸浸液中氟和铈

氟碳铈矿是最主要的稀土来源,而氟是制约稀土清洁化分离的瓶颈,因此在提取稀土前进行氟的分离是一种解决方案。利用氟铝间很强的配位性质,加入铝盐而发生竞争配位反应,使[CeF2]2+变为游离Ce4+后向萃取相转移,实现氟-铈分离。实验结果表明:[H+]≤1.0mol.L-1,以Al2(SO4)3或NaAlO2为氟络合剂,根据酸浸中F-含量,向浸出液中加入n(F)/n(Al)=1的Al2(SO4)3或n(F)/n(Al)=1.5的NaAlO2时,氟-铈分离效果最好。     

Thermodynamic Approach to Substantiating the Work and Potential for Separation of Multicomponent Mixtures

Russian Journal of Physical Chemistry A - Equations for calculating the thermodynamic work of separation are proposed and generalized.     

Task Specific Onium Salt as Soluble Support in Multicomponent Synthesis of 4-Aryl-2-amino-3-ethoxycarbonyl-naphthopyrans

In this paper was presented an application of task specific onium salt as soluble support in multicomponent synthesis of 2‐amino‐3‐ethoxycarbonyl‐naphthopyrans. The starting task‐specific onium salt was functionalized in good yield with chloroethyl alcohol, followed by three steps containing esterification, three components reaction and cleavage from onium salt to afford naphthopyrans in 60% –88% overall yields. All of the products were characterized by IR, ¹H NMR, ¹³C NMR and MS techniques.     

熔盐电解法制备镁稀土合金的现状及展望

熔盐电解法是一种高效制备镁稀土合金的方法,工艺流程简便易于连续生产,而且制备的镁稀土合金成分均匀,不偏析。 不同稀土元素的熔盐体系也有所区别,重稀土元素一般采用氧化物电解法,而轻稀土元素则采用氯化物电解法。 针对以上不同的电解方法,本文从电解原料、电解槽结构、电极过程、电解工艺、尾气处理等多方面详细阐述了制备镁稀土合金的现状,并对电解法制备镁稀土合金的未来提出发展方向。     

Anti-HIV Active Naphthyl Analogues of HEPT and DABO

 5-Isopropyl-6-naphthyl uracil and 5-isopropyl-6-naphthyl-2-thiouracil were alkylated to give N-1-(ethoxymethyl and methylthiomethyl) uracil and S²-cyclohexyl-thiouracil, respectively. 5-Ethyl-6-naphthyl uracil and 5-ethyl-6-naphthyl-2-thiouracil afforded N-1-(ethoxymethyl, methoxy-methyl, methylthiomethyl, acetoxyethoxy methyl and hydroxyethoxy methyl) uracil and S²-((2,2- diethoxyethyl), methoxycarbonylmethyl, ethoxycarbonylpropyl, methylthiomethyl, ethoxymethyl, methyl and cyclohexyl)-thiouracil upon alkylation.     

颗粒内受限聚合法制备PP/POE/PS合金

以等规聚丙烯/乙烯-辛烯共聚物(PP/POE)合金颗粒为扩散基体, 苯乙烯(St)为扩散单体, 利用颗粒内受限聚合法制备了PP/POE/PS三元合金. 结果表明, 对于POE质量分数为20%~40%的PP/POE合金颗粒, St均可扩散至直径为4 mm的颗粒中心部位, 在POE非晶相中生成相尺寸为几十至几百纳米的PS球. 在PP/POE合金颗粒的不同部位, 因POE相尺寸及单体的吸附量不同, 生成的PS相尺寸也不同, 在颗粒中心部位生成的PS球最小. 研究了St在PP/POE(质量比80: 20)颗粒中的扩散-聚合行为, 结果表明, St在合金颗粒中的扩散速率和扩散饱和值远大于在纯PP颗粒中的扩散速率和饱和值, 这主要是因为PP/POE合金颗粒中的非晶POE相有利于扩散. 改变单体投料量可以获得具有不同PS含量的PP/POE/PS三元合金. 结晶性能研究结果表明, PS在非晶POE相中的优先分布会使POE相体积增大, 从而使PP的结晶温度和熔融温度降低. 随着PS量的进一步增大, 分布在PP中的PS对PP有结晶成核作用.     

电感耦合等离子体原子发射光谱法测定铜合金中磷

在pH 3～4的微酸性介质中,铜合金试样溶液通过装有强酸性聚苯乙烯型阳离子交换树脂的离子交换柱,分离除去其基体金属阳离子.交换柱流出液(包括洗液)经酸化,蒸发浓缩并定容为25 mL后,用电感耦合等离子体原子发射光谱法测定此溶液中磷(以PO3-4形态存在)的含量.方法的检出限(3σ)为0.026 mg·L-1,用标准加入法测得方法的平均回收率为101.9%.     

Engineering Migration Pathway for Effective Separation of Photogenerated Carriers on Multicomponent Heterojunctions Coated with Nitrogen-Doped Carbon

Multicomponent NiTiO₃/A-TiO₂/R-TiO₂ photocatalysts coated with nitrogen-doped carbon (N-C/NiTiO₃/A-TiO₂/R-TiO₂) for efficient H₂ production were fabricated by directly pyrolyzing NH₂-MIL-125(Ni/Ti) metal–organic framework microrods. Owing to the synergistic effect of the N-doped carbon coating layer and multicomponent heterojunctions, the H₂ production rate of N-C/NiTiO₃/A-TiO₂/R-TiO₂ was even higher than that of its Pt-containing counterpart (Pt/NiTiO₃/A-TiO₂/R-TiO₂). N-C/NiTiO₃/A-TiO₂ and N-C/NiTiO₃/R-TiO₂ as control photocatalysts were also prepared by simply adjusting the calcination temperature of NH₂-MIL-125(Ni/Ti) in air atmosphere. The H₂ production rate followed the order of N-C/NiTiO₃/A-TiO₂/R-TiO₂>N-C/NiTiO₃/A-TiO₂>N-C/NiTiO₃>R-TiO₂, which indicates that the multicomponent heterojunction plays a key role in photocatalytic H₂ generation. The mechanism for the influence of the multicomponent heterojunction on photocatalytic activity was investigated in combination with molecular simulations, which showed that N-C/NiTiO₃/A-TiO₂/R-TiO₂ has a so-called double type II heterojunction providing a perfect step-by-step migration pathway for effective separation of photogenerated electrons and holes. This work presents a simple and effective method for synthesizing efficient multicomponent photocatalysts.     

Studies on the Effects of Salt and Surfactant in Wet Phase Separation of Polysulfone

This study investigates the effect of additives in the nonsolvent water in terms of cloud point during the phase inversion of Polysulfone (PS) in dimethyl formamide (DMF). The exponential pattern is observed with PS concentration (0.2 to 0.6% (w/w)). It needs a low amount of water to get the cloud point at low temperature. The cloud point varied with the nature of water matrix and depended on the amount of salt, as well as the PS amount. The presence of salts (sodium chloride and sodium sulfate) lowers the cloud point of the solution. The network distribution of the particles at the cloud point is disturbed in the presence of salt. The requirement is more for Sodium lauryl sulfate (SLS) added water to reach the cloud point in the low range of PS solution up to 0.3% PS (w/w). The morphological and distribution pattern of PS particles are very different compared to PS particles produced from pure water. XRD study of PS particles produced from the mixed water system reflects relatively more amorphous character with respect to PS particles from pure water. The presence of both surfactant and salts in water systems also influences the cloud point in synergistic manner.     

A Study of the Competitive Equilibrium in Ion Exchange of Calcium(II) on Zirconium Phosphate in Multicomponent Salt Solutions

A sorption technology for stabilization of multicomponent salt solutions (wines) subject to calcium clouding is being developed on the basis of an inorganic cation-exchanger of Termoksid-3A brand. In this connection the ion-exchange equilibrium on a zirconium(IV) phosphate of Termoksid-3A brand in multicomponent solutions at pH 2.5 – 3.0 was studied. The selectivity series of the sorbent were determined in relation to the solution composition.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 2, 2005, pp. 235–239.Original Russian Text Copyright © 2005 by Borovkov, Sharygin.     

Separation of Cobalt and Tungsten Carbide by Anodic Dissolution of Hard Alloys in Phosphoric Acid Solutions

Anodic behavior of the VK-6 alloy in phosphoric acid solutions was studied potentiometrically, voltammetrically, and by X-ray phase and metallographic analyses. The potential range was determined in which the phase of cobalt-tungsten alloy dissolves with formation of soluble compounds of the above metals and the tungsten carbide phase does not dissolve. The results obtained can be used in reprocessing of hard alloy scrap.     

多组分参与的氟烷基化反应研究进展

多组分参与的氟烷基化反应是当前有机氟化学研究的一个热点.在过去的几年里,由于新试剂新方法的不断涌现,多组分参与的氟烷基化反应取得了长足的进展,不仅可以经济有效地一步将氟烷基基团与其他官能团同步引入,而且可以将起始原料转化为多种含有生物活性或药物活性的化合物.按照三组分二氟烷基化反应、三组分三氟甲基化反应、三组分全氟烷基化反应、三组分单氟烷基化反应、三组分氟化反应以及四组分氟烷基化反应和总结7个部分,总结了多组分参与的氟烷基化反应在过去近十年时间里的发展进程,同时对该类反应进行了总结和展望.