化学镀镍诱发过程的研究 Ⅱ.用电子能谱研究诱发过程

本文用AES和XPS的表面分析和深度剥离技术研究了“催化金属”诱发时间不同时,基体铜表面上镍、铜、磷等元素含量的变化及其深度分布。结果表明,在化学镀镍层中存在薄的吸附层,它由C、Cl、O、S等组成,主要的吸附物是C和O。吸附层下面是正常的化学镀镍层,它的Ni/P比约为2。在靠近基体金属表面存在Ni/P比变化的交界层。最后是Ni、P扩散到基体铜上的Cu-Ni-P合金层,它们的Cu∶Ni∶P≈56∶36∶5,这是化学镀镍层与基体金属结合力特别好的原因。用铁诱发0.5s的铜片上用AES未检出铁,却检出了大量镍,而且铜的主要AES峰已为镍取代,表明诱发反应是典型的“一触即发”反应。AES未能检出铁,表明诱发反应不是诱发金属先在基体金属上沉积而后发生的。     

线性变位极谱法研究——Ⅻ.CAEM过程二次导数配位吸附不可逆波理论及其验证

本文提出了CAEM过程线性变位二次导数极谱配位吸附不可逆波理论,并以铜(Ⅱ)-L-组氨酸—氢氧化钠体系进行验证,理论与实验结果相一致.     

可逆逐级电子转移过程的1.5次和2.5次微分新极谱法

本文提出了可逆逐级电子转移过程(n_1=n_2)的1.5次和2.5次微分电分析法(卷积伏安法)的理论公式,用计算机绘出了相应的理论曲线图,讨论了标准分离电位(△E~0)及电子转移数(n)对电流～电压曲线的影响.选用氯化铜(Ⅱ)-氨水-氯化铵体系进行了实验验证,其结果与理论完全相符.     

盐酸环丙沙星的示波极谱测定及其机理研究

在ＰＨ６．９的ＫＨ２ＰＯ４－ＫＯＨ缓冲液中，盐酸环丙沙星在滴汞电极上产生一灵敏的催化氢波。峰电位为－１．５１Ｖ，在１．００×１０＾－７－２．００×１０＾－５ｍｏｌ．Ｌ＾－１之间有良好的线性关系，用于对盐酸环丙沙星的测定，方法简便、结果准确可靠。     

羟基蒽醌衍生物中羟基质子的核磁共振研究

通过对23个羟基蒽醌衍生物的质子核磁共振研究, 观察了不同取代类型羟基的化学位移范围;讨论了酚羟基乙酰化对芳环质子的化学位移影响, 为羟基取代位置的确定及芳环质子谱线归属提供了某种判据.此外, 还用HMO 法探讨了各类取代羟基的氢键强度及羰基迫位仅有一个羟基的内氢键强度与给予原子电荷密度的关系.本文报道一系列新型冠醚N,N'-双取代-1,7-二氧杂-12-冠-4(1~6), N,N' -双取代-1, 7-二氮杂-15冠-5(7~10) 及N,N'-双取代-1,10-二氮杂-18-冠-6(11~14)的质谱. 借助联动扫描和去焦技术对它们的开裂机理作了详细探讨.     

氨基酸电位波谱分析机理的研究

本文研究了镍与酪氨酸、胱氨酸、脯氨酸、亮氨酸形成的四组络合物,在pH=10的Na_2B_4O_7·10H_2O-CH_3CHO-NaOH体系中,应用示波极谱进行电位扫描,出现四组灵敏度和分率辨均很高的电位波谱,为同时连续测定多组份共同存在的氨基酸分析方法提出一条新的途径。     

光化学反应的极谱法研究及应用

光化学反应的极谱法研究及应用蒋治良，王盛杰（广西师范大学计算分析测试中心，桂林５４１００４）光化学反应的极谱分析法系基于物质吸收了紫外－可见辐射能而引起诸如光分解、光加成、光氧化还原及光异构等光化学反应，导致物质的结构或性质发生了某些变化，诸如形成了...     

化学镀镍诱发过程的研究 I:金属催化活性的鉴别和反应机理

Electroless plating is known to be an autocatalytic process. For the reaction to start, the substrate metall should be either catalytic or activated by a suitable catalyst. For example, steel and nickel can be plated directly, but in the case of copper or brass, catalytic metal inducing is need. In this paper, the catalytic activity of different metals and their inducing effects were in vestigated by measuring stationary potentials nd stationary potential-time curves. Experimental results showed: (1) The stationary potential of metal provides a simple parameter to estimate the catalytic activity of metals in electroless nickeling. When 1-hydroxyethylidenediphosphonic acid (HEDP) aelectroless nickeling bath containing NaH2PO2 as reducing agent is used, electrolessnickeling may proceed spontaneously, if the stationary potential of metal is more nagative than -0.60V, no matter whether nickel (autocatalytic active) or other metals(non-autocatalytic active) is used as substrate. (2)When an autocatalytic meta is in contact with the substrate metal in the bath, a sudden decrease of stationary potential is observed. The whole inducing process could be finished within 0.5-2 sec. (3) The stationary potential of electroless nickeling coating in HEDP bath at 80`C is-0.72V, consequently nickel coating itself is a catalytic active metal. Once an electroless nickeling coating is deposited on a substrate metal, electroless nickeling reaction can then proceed continuously. (4) The sufficient conditions of electroless nickeling in HEDP bath containing NaH2PO2 are that the stationary potential of substrate metal must be more nagative than -0.60V and that the temperature of electroless nickeling bath should be higher than 50`C. (5) Inducing mechanism of electroless nickeling can be explained with chemical cell consisting of substrate metal and catalytic metal. Electrons from catalytic metal would suddenly decrease the stationary potential of substrate metal, H+ and Ni2+ complex ion would be reduced on the substrate me     

从2AlCl3/Et3NHCl离子液体中电沉积制备Ni 和Ni-Al 合金

在含Ni2+的2AlCl3/Et3NHCl离子液体中的铜电极上通过恒电位电沉积制备出金属Ni和Ni-Al合金.采用循环伏安和计时电流方法,揭示铜电极上沉积金属Ni的成核机理,研究了电沉积Ni-Al合金的机理,以及恒电位沉积Ni-Al合金工艺条件对沉积Ni-Al合金表面形貌和电流效率的影响.结果表明:在铜电极上电沉积金属Ni的成核机理为受扩散控制的三维瞬时成核过程.在电量≥3.0 C时,电沉积Ni-Al合金的组成基本不再变化.Ni-Al合金的电沉积机理为,Ni的电沉积受扩散控制,同时进行Al的欠电位沉积,在Ni-Al合金电沉积过程中某些Ni-Al合金相的沉积可能受动力学限制而使Ni-Al合金的组成偏离热力学预测结果.在电沉积Ni-Al合金的沉积电流小且平稳,电沉积速率慢条件下,Ni-Al合金表面形貌致密均一,反之就会出现瘤节.电沉积Ni-Al合金的电流效率＞90％.电沉积物的组成接近于Ni3Al合金.     

Spontaneous near-substrate composition modulation in electrodeposited Fe–Co–Ni alloys

Conventional and reverse depth profile analysis of electrodeposited Fe–Co–Ni alloys was performed by secondary neutral mass spectrometry (SNMS). It was found that the reverse sputtering method gave a much better depth resolution at the vicinity of the substrate. The reverse SNMS spectra showed that the deposition of Fe–Co–Ni alloys starts with the formation of an Fe-rich zone followed by an increase in Co concentration, then the nickel content increases and a steady-state alloy composition is achieved. At high current density, the initial depth pattern reproduces itself twice before the composition becomes stable. It was concluded that the varying depth profile is a consequence of the anomalous nature of the codeposition of the alloy components, the depletion of the electrolyte with respect to the metal salts, and the dependence of the intensity of the hydrogen evolution on the deposit surface composition.     

Energy‐damping behaviors of poly(methyl acrylate‐co‐divinylbenzene) microspheres coated with a porous nickel–phosphorus layer

Hybrid microspheres of poly(methyl acrylate‐co‐divinylbenzene) (PMADVB) with a thin and porous nickel–phosphorus (Ni–P) alloy layer were prepared via suspension polymerization and electroless nickel plating. The characterization of pristine and nickel‐coated microspheres was carried out with a differential scanning calorimeter and a scanning electron spectroscope equipped with an energy‐dispersive system. The glass‐transition range of Ni–P‐coated PMADVB was broadened and extended in the higher temperature direction. This effect allowed the PMADVB network to embrace more diversified energy states of the segment motion, this being a desired feature for damping sound waves. The low‐frequency (100–1000‐Hz) sound absorption behavior of the microspheres was tested with a sound attenuation kit. Besides the testing of their low‐frequency damping performance, an investigation into the ultrasonic‐wave (～35 kHz) absorption feature of the microspheres was conducted through chemical means; that is, the attenuation to the ultrasonic wave with respect to the unprotective situation was assessed through the chemisorption extent of copper ions on a biomass adsorbent. The Ni–P deposition layer was found to augment the damping capacity of the polymer network. The alloy layer was determined to cause an expansion of the glass‐transition range of PMADVB and its wave‐scattering capability because this layer was made up of submicrometer metallic grains. In this work, the particulars of the metal–polymer interactions were associated with a core–shell structure. The metal outer layer was thought to create a spherical temperature field inside the PMADVB network, and concerted motions of the polymer segments resulted. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2710–2723, 2004     

Cathodic stripping voltammetry of nickel: sonoelectrochemical exploitation of the Ni(III)/Ni(II) couple

The exploitation of the Ni(III)/Ni(II) transition as a means of quantifying the concentration of nickel within industrial samples was assessed. The methodology relies upon the reagentless electrodeposition of Ni onto a glassy carbon electrode and the subsequent oxidative conversion of the metallic layer to Ni(III). The analytical signal is derived from a cathodic stripping protocol in which the reduction of the Ni(III) layer to Ni(II) is monitored through the use of square wave voltammetry. The procedure was refined through the introduction of an ultrasonic source which served to both enhance the deposition of nickel and to remove the nickel hydroxide layer that results from the measurement process. A well-defined stripping peak was observed at +0.7 V (vs. AgAgCl) with the response found to be linear over the range 50 nM to 1 μM (based on a 30 s deposition time). Other metal ions such as Cu(II), Mn(II), Cr(III), Pb(II), Cd(II), Zn(II), Fe(III) and Co(II) did not interfere with the response when present in hundred fold excess. The viability of the technique was evaluated through the determination of nickel within a commercial copper nickel alloy and validated through an independent comparison with a standard ICP-AES protocol.     

溶剂化金属原子浸渍法制备高分散负载型催化剂(Ⅶ)——Ni-Cu/SiO2双金属催化剂的结构与性能

利用金属蒸气法制备了不同组成的Nj-CujSiO₂双金属催化剂,XRD、TEM和磁性测定表明有Ni-Cu合金形成,合金颗粒的组成不均匀,而且有部分自由的Ni和Cu存在;Ni/Cu摩尔比为1:1催化剂的催化活性大于2:1和3:1的双金属催化剂以及Ni和Cu的单金属催化剂。     

Electrochemical processes during plating Fe powder particles by Ni and Ni/Cu coating in the fluidized bed

Ni electrodeposition on Fe powder was studied with respect to an inhibiting adsorbed hydroxycomplex layer. Its elimination was done in three possible ways: by increasing the rotation speed of the circular stirring of the suspension, by chemical dissolution of the adsorbed layer during interrupted electrolysis, and by addition of a complexing agent – sodium citrate into the electrolyte. The simultaneous deposition of a Cu/Ni coating was enabled by proper electrolyte composition as to the ratio of both metallic compounds and by the addition of a suitable complexing agent. The Cu/Ni ratio was influenced, beside electrochemical parameters, also by the particle size of the Fe powder and by the suspension density. Increasing the suspension density supports the deposition of Ni, and increasing the particle size supportsthe deposition of Cu. Electronic Publication     

Ni80P20合金的非晶化度与催化活性的关联

采用淬冷法,通过改变冷却铜辊的转速,得到了一系列具有不同非晶化度的Ｎｉ８０Ｐ２０合金材料。以乙炔加氢为探针反应的催化研究结果表明,合金的催化活性随非晶化程度的增加而增加,同时,非晶态合金具有比相应的晶态金合明显优良的催化稳定性,ＸＲＤ和ＡＥＳ深度分析显示：在氧化－还原活化处理过程中,相对晶态合金而言,非晶态合金显示明显的“惰性”,活化后的表面上含有较多的对加氢反应有促进作用的氧化镍相互作用的结构。     

PROPERTIES OF Ni-Cu/SiO_2 BIMETALLIC CATALYSTSPREPARED BY SOLVATED METAL ATOM DISPERSION(SMAD) TECHNIQUE

IntroductionAsoneofthemethodsofpreparationofsupportedmetalcatalysts,solvatedmatalatomdispersion(SMAD)onoxidesupportsattractsmuchattentionnowadays.TIstechniquehasbeendevelopedbyKlabunde'SandOzin'sresearchgroups.Itprovidesanumberofadvantages,ascomparedwitht…     

Copper nanoparticles seeded functionalized‐PVC plastic surface for electroless nickel deposition

A novel and facile activation process for electroless nickel deposition was developed. The semi‐interpenetrating polymer network hydrogel biofilm was used to functionalize the inert poly(vinyl chloride) (PVC) surface, and then Cu nanoparticles, which can initial the subsequent electroless nickel deposition successfully seeded on the functionalized‐PVC surface. The samples were characterized by scanning electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, and transmission electron microscopy. The results show that the hydrogel film provided the PVC surface with amino groups and Cu nanoparticles of 20–50 nm in size could be functioned as the catalytic nuclei for the subsequent electroless metal deposition on PVC plastic. It can be concluded that the novel Cu activation was effective for the nickel deposition on PVC surface, because of more chemisorption sites for Cu nanoparticles generated on PVC surface. Copyright © 2013 John Wiley & Sons, Ltd.