Accumulation of Cu(II) cations in poly(3,4-ethylenedioxythiophene) films doped by hexacyanoferrate anions and its application in Cu-selective electrodes with PVC based membranes

Electrochemical properties of poly(3,4-ethylenedioxythiophene) doped with hexacyanoferrate(II,III) ions (PEDOT(HCF)) were studied in the presence of Cu²⁺ ions. Voltammetric and EDAX studies revealed retention of hexacyanoferrate anions in the polymer film and accumulation of Cu(II) cations, as well as formation of solid copper hexacyanoferrate near the polymer surface.Accumulation of Cu²⁺ ions was found to be advantageous from the point of view of PEDOT(HCF) applications as a solid contact (ion-to-electron transducer) in all-solid-state Cu²⁺-selective electrodes with solvent polymeric polyvinyl chloride (PVC) based membrane, containing Cu²⁺-selective ionophore. Binding of Cu²⁺ ions in the conducting polymer layer results in analyte ions flux into the transducer phase. Thus, pronounced enhancement of selectivity of the all-solid-state Cu²⁺-selective electrode or lower detection limit of the potentiometric response range was achieved, reaching under optimised conditions 10⁻⁷ M CuSO₄.     

Investigation of transport phenomena in a hybrid ion exchange-electrodialysis system for the removal of copper ions

Hybrid ion exchange electrodialysis processes allow the removal of metal ions from dilute waste liquids and the recovery of more concentrated solutions. The work reported here was aimed at investigating the two steps in the treatment process, namely, adsorption of metal ions onto the packed bed of resin and electromigration (i.e., the transport of these ions in the complex system under the applied electrical field). The case of copper sulfate was investigated. Dowex resins with a cross-linking degree of 2 and 8% were used. The flux of copper through the resin bed and the current efficiency for ion transfer to the cathode compartment were determined as a function of potential gradient and copper ionic fraction in the bed. Apparent diffusion coefficients of Cu²⁺ in the overall system were deduced from the experimental data.     

Al2O3／TiB2／SiCW陶瓷刀具加工镍基合金时的磨损机理研究

研究了Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ陶瓷刀具加工Ｉｎｃｏｎｅｌ７１８镍基合金时的切削性能和磨损机理。结果表明；在低速切削条件下，Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ和硬质合金刀具的抗后刀面磨损的能力相差不大；而在高速切削条件下，前者的抗后刀面磨能力远高于后者。     

An evaluation of commercial nickel catalysts during hydrogenation of soybean oil

The activities of several commercial nickel catalysts were determined by measuring their activation energies. Among these catalysts, G95E, Resan 22, Nysosel 222 and 325, all with low activation energy, were more active than DM3 and G95H, which had higher activation energy. However, the less active catalysts increased the linoleate selectivity of soybean oil during hydrogenation. The yields of bothtrans isomers and winterized oil were higher for the more selectively hydrogenated oil catalyzed by the less active catalysts. In the sensory evaluation, the fractionated solid fat that contained moretrans isomers was lower in flavor scores than the fractionated liquid oil after hydrogenation and winterization of soybean oil.     

Electrodeposition of catalytically active nickel for the oxygen evolution reaction — effects of anionic composition

Nickel electrodes were prepared by electrodeposition in electrolytes of various anionic compositions. The deposition conditions and bath types were evaluated with special emphasis on the electrocatalytic properties for the oxygen evolution reaction (OER). Electrochemical characterizations in a 5 mol/L KOH solution at 25°C showed that the electrode deposited from the chloride bath, having a low Tafel slope of 50 mV/dec and an overpotential of 396 mV at 100 mA/cm², is the most catalytically active among electrodes prepared in electrolytes of various anionic compositions. The electrode activity for the OER is related to the real surface areas, which depend on the anion compositions in the deposition bath and the deposition conditions.     

光亮镀镍液pH值计算机控制系统

光亮镀镍液的ｐＨ值控制得稳定否，对于镀层质量有重要的影响，本文介绍了在电镀生产过程中，对镀镍液的ｐＨ值进行自动控制的一个计算机系统，该系统在广州五羊自行车厂电镀车间投入使用后，镀件质量有了明显的提高。     

配合物[Ni(IDB)_2][C_6H_4(OH)COO]·ClO_4·CH_3CH_2OH·H_2O催化尿素水解的机理及其电化学性质

报道[Ni(H2O)6](ClO4)2·2H2O的合成、晶体结构,单核镍(Ⅱ)配合物[Ni(IDB)2][C6H4(OH)COO]·ClO4·CH3CH2OH·H2O[配体IDB为N,N 二(2 苯并咪唑亚甲基)胺]的电化学性质,探讨标题配合物催化尿素水解的机理。X射线单晶衍射表明,[Ni(H2O)6](ClO4)2·2H2O晶体属单斜晶系,P2(1)/C空间群,化学式:Cl2H16O16Ni,Mr=401.74,晶胞参数:a=0.62383(12)nm,b=1.2464(3)nm,c=0.91845(18)nm,α=90°,β=106.93(3)°,γ=90°,V=0.6832(2)nm3,Z=2,F(000)=412,S=1.079,DC=1.953g/cm3,μ=1.890mm-1。最终因子R[I>2σ(I)]:R1=0.0423,wR2=0.1155;R(全部数据)∶R1=0.0506,wR2=0.1180。结构分析表明,[Ni(H2O)6](ClO4)2·2H2O的镍(Ⅱ)分别与6个H2O配位形成对称的正八面体构型。循环伏安实验说明,标题配合物在DMF溶液中在E1/2=0.884V处经历了一个准可逆的一电子氧化还原过程。     

Homogeneous Catalysis for the Production of Fine Chemicals. Palladium- and Nickel-Catalysed Aromatic Carbon–Carbon Bond Formation

In this article we describe our recent efforts in the area of palladium- and nickel-catalysed aromatic substitution reactions. Main focus is on low cost and low waste production methods. The use of aromatic carboxylic anhydrides in the Heck reaction leads to a waste-free protocol. In addition these reactions are easy to work up as no ligands or bases are used. For Heck reactions where substrates or products do not tolerate high temperatures we found that use of a bulky phosphoramidite (13b) as ligand for palladium leads to a very fast reaction at low temperatures. Recycle of palladium in ligand-free Heck and Suzuki reactions is easily accomplished by treating the palladium black that precipitates at the end of the reaction on a carrier material with a small excess of I₂ prior to its re-use in the next run. Use of aryl chlorides in the palladium- and nickel-catalysed formation of biaryls can be accomplished by using the nickel-catalysed coupling with arylzinc chlorides. Better still, it was possible to make use of the arylgrignard and use a catalytic amount of ZnCl₂. Whereas the strength of these aromatic substitution reactions lies in their broad tolerance of functional groups, one exception was the Sonogashira reaction on 3-bromoaniline. The problem was solved by making use of in situ catalytic protection of the NH₂ group with benzaldehyde.     

适用于摩托车零件的多层镍电镀工艺

概括目前我国摩托车零件电镀所用镀层组合，对照有关金属覆盖层的国家标准，认为摩托车零件应用多层镍组合，并提供了工艺配方。     

溶液中钙离子对玻璃颗粒电泳沉积的影响

研究了玻璃颗粒在乙醇溶液中对Ca^2 的选择吸附，反转了玻璃颗粒在乙醇中的荷电性质，使玻璃颗粒能够在乙醇中与羟基磷灰石发生共沉积。讨论了不同离子浓度下电泳沉积的沉积量与沉积电流的变化情况，并以此对Ca^2 在电泳沉积中的作用进行了分析。实验结果证实：悬浮液中Ca^2 或吸附到玻璃颗粒上，改变其荷电性质；或留在溶液中，作为电泳沉积过程中电流的主要承载者。离子浓度对电泳沉积的效果有重要的影响，离子浓度太低或太高都易使涂层出现缺陷。分析了不同沉积条件下电泳沉积所得涂层的各种缺陷及其成因。