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Conductivities of AlCl3/Ionic Liquid Systems and Their Application in Electrodeposition of Aluminium
Solubilities and conductivities of anhydrous AlCl3 in six kinds of ionic liquids (ILs) were measured. Among the six kinds of ILs [bmim]Cl, [bmim]Br, [bmim]BF4, [bmim]PF6, [emim][EtSO4] and [bmim][HSO4], anhydrous AlCl3 could be dissolved in the first five kinds but was hardly dissolved in [bmim][HSO4]. The results showed that the nominal solubilities of AlCl3 in ILs increased in the order of [bmim][HSO4] < [bmim]PF6 < [emim][EtSO4] < [bmim]BF4 < [bmim]Cl < [bmim]Br. Conductivities of the AlCl3/ILs systems depended apparently on the nominal molar ratio of AlCl3 to ILs. The conductivities of AlCl3/[bmim]Cl, AlCl3/[bmim]Br and AlCl3/[bmim]PF6 systems had a similar tendency as a function of the nominal molar ratio, that is, as the molar ratio was increased, conductivities increased first and then decreased, with the maximum conductivity obtained at approximately 0.9:1, 1.0:1 and 0.5:1, respectively. Conductivities of the AlCl3/[bmim]BF4 exhibited a dentate change and decreased with the molar ratio of AlCl3 to [bmim]BF4 increasing in general. With the increasing of the anhydrous AlCl3 amount in [emim][EtSO4], conductivity of AlCl3/[emim][EtSO4] monotonically decreased. AlCl3/[bmim]Cl system was chosen as the electrolyte for the electrodeposition of Al. Preliminary experimental results showed that dense, adherent and homogeneous Al coatings could be electrodeposited on stainless steel by means of constant potential technique and the surface coverage was quite satisfactory. 相似文献
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Zinc and indium were deposited from sulphate and chloride electrolytes onto aluminium electrodes under potentiostatic conditions. The role of the anion, pH, cation concentration, cathodic potential and agitation were investigated. The deposit morphology and composition were studied by SEM and EDX. Potentiodynamic and galvanostatic techniques were also applied for product characterization. Once a critical amount of Zn was deposited preferred In deposition began without agitation. But under rotation or at low cathodic potentials Zn2+ discharge became the prevalent reaction. The results support the earlier hypothesis of the preferential adsorption of Zn ions [1]. 相似文献
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B. Bozzini C. Mele L. D’urzo G. Giovannelli S. Natali 《Journal of Applied Electrochemistry》2006,36(7):789-800
This paper deals with the effects of PEG during Cu electrodeposition from an acidic sulphate solution. This investigation was carried out with electrochemical and spectroelectrochemical techniques. Potentiostatically grown layers were examined by scanning electron microscopy. Adsorption of PEG on the growing Cu surface can be inferred from electrokinetic, SERS and morphological evidence: variations of the estimated exchange current density, qualitative and quantitative differences in the potentiostatic transients, changes on the cathodic current efficiency, effects on the three-dimensional crystallisation mode under both compact and dendritic growth conditions, appearance of surface-enhanced PEG-related Raman bands. SERS spectra revealed cathodic reactivity of adsorbed PEG. 相似文献
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在石墨粉经硝酸粗化、蒸馏水洗涤、烘干等处理,并均匀分散的电镀液中,进行复合电沉积,再经热处理、冷却制备铜一石墨复合材料.通过SEM、布氏硬度、电导率、拉伸及摩擦磨损性能的测试分析表明:在该工艺条件下制备的电沉积铜-石墨复合材料具有良好的导电性、自润滑性反摩擦磨损性能. 相似文献
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The electrochemical behaviour of copper has been investigated in different cupric complex solutions by cyclic voltammetry. In pyridinic and picolinic solutions the reduction of cupric complex occurred in two stages leading to Cu(I) and Cu(0), respectively. The electrodeposited copper is oxidized in two steps leading to Cu(I) and Cu(II) as in ammoniacal cupric complex solutions. In glycine, alanine, sulfamic acid and ethylenediamine solutions, the cuprous complex is an intermediate in the cupric complex reduction but it is not detected during the oxidation of the electrodeposited copper in these solutions. In EDTA and triethanolamine solutions, the cuprous complex is not observed. The rate of copper etching was determined in pyridinic and ammoniacal cupric solutions and was shown to be faster in ammoniacal cupric solutions than in the pyridinic solutions. 相似文献
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Nucleation and growth of copper electrodeposited on chromium plated electrodes in copper sulfate electrolytes were examined, focusing on the influence of prior Cr plating conditions on the nucleation density and growth kinetics of the copper electrodeposits. The Cr-plated electrodes were made by electrodeposition of Cr on copper sheets for 2 to 60 s at 0.1 A cm–2 in CrO3 350 g L–1 + H2SO4 3.5 g L–1. Copper was then electrodeposited onto the Cr-plated electrode under potentiostatic conditions. Copper initially nucleated and grew according to a three-dimensional diffusion controlled progressive nucleation process, and later according to an instantaneous nucleation process. The period during which copper nucleation is controlled by the diffusion controlled progressive nucleation process decreases with increasing Cr plating time. The nucleation density of copper was extremely high on the 2 s Cr-plated electrode, producing an extremely fine and uniform electrodeposit. However, on the 4 s Cr-plated electrode, the nucleation density of copper significantly reduced to one hundredth of that on the 2 s Cr-plated electrode, and then decreased slightly with increasing Cr plating time (thickness of Cr layer). These results appear to be associated with the IR drop across the Cr layer, including the surface Cr oxide/hydroxide film (termed the cathode film), which significantly reduces the driving force for the electrodeposition of copper under potentiostatic plating conditions. 相似文献
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An analytical electrochemical cell based on the Hull cell is described. The cell was tailored specifically for the analysis of electrowinning or electroplating. Current density distributions were generated by asymmetric insertion of an insulating baffle between parallel electrodes. The position and length of the baffle were easily altered, giving 12 possible distributions for a single total current. The cathode consisted of 10 electrically isolated 1cm2, aluminium segments. By logging the potential drop across 1 resistors in each of the 10 isolated parallel branches, quantitative determination of current densities across the cathode was made possible. The small segments facilitated microscopic analysis of deposit morphologies. A technique for the determination of current efficiencies on each segment is described and demonstrated. The technique obviates the necessity to determine deposited masses directly. Development of the technique for industrial application is detailed. The system is demonstrated by evaluating known effects of variables in zinc electrowinning. The variables examined were temperature, deposition time, acid concentration and antimony contamination. 相似文献
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以磷酸溶液为电解液、以高纯铝为阳极,采用两步阳极氧化法制备氧化铝模板。扫描电子显微镜(SEM)对其表面形貌分析表明,氧化铝膜为多孔结构,膜孔径随着阳极氧化电压的增大而不断增大。对阳极氧化电流密度变化分析证实,铝的阳极氧化经历了三个阶段:阻挡层的生成、多孔层的形成和多孔层的稳定生长。以制备的氧化铝膜为阴极、锌片为阳极,以硝酸锌和硼酸的混合液为电解液,采用交流电沉积方法制备了针状氧化锌纳米线。 相似文献
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选用异佛尔酮二异氰酸酯(IPDI)、封闭剂丁醇(BO)、可阳离子化扩链剂三乙醇胺(TEOA)合成了用于阴极电泳涂料的阳离子型丙烯酸酯树脂和阳离子型封闭异氰酸酯固化剂。通过傅里叶变换红外光谱(FT-IR)对合成的树脂和固化剂进行了表征;用差示扫描量热(DSC)、热重分析(TGA)测定了丙烯酸阳离子树脂电泳漆的固化行为。结果表明:丁醇封闭的阳离子型封闭异氰酸酯解封温度为117℃,电泳漆膜的实际起始固化温度为140℃左右,在180℃、30 min可固化完全。并通过粒径变化对电泳乳液的稳定性进行了探讨,发现乳液平均粒径为164 nm,稳定性较好,具有工业应用前景。 相似文献
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8407钢是常用的铝合金压铸用模具钢.为改善模具的抗热疲劳和抗熔损性能,对冷喷涂A1后的8407钢试样在500,550℃下进行扩散处理,渗铝后的试样在纯O2气氛,570℃的条件下进行氧化,渗层表面形成了Fe-A1-O的混合氧化物.考察了扩散温度和扩散时间对渗层质量的影响,研究了在纯O2气氛下Fe-A1合金表面的氧化情况.结果表明,8407钢经过冷喷涂铝后再进行低温扩散处理能够实现低温渗铝.渗铝后,在580℃以下,纯O2气氛条件下氧化,Fe-A1合金表面生成了FeO和.A12O3的混合氧化物.该氧化膜与铝液不润湿,可防止粘膜并改善模具的抗热疲劳和抗熔损性能. 相似文献
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Some aspects of the electrodeposition of copper and cobalt from aqueous sulphate solutions containing low concentrations of their ions were studied with a view to heavy metal removal via an electrochemical process. Both metals were deposited on a vitreous carbon rotating disc electrode. Deposits formed under different conditions were studied employing linear sweep voltammetry, scanning electron microscopy and EDAX surface analysis. Constant potential electrolysis was used to simulate recovery in a laboratory batch reactor. Copper can be deposited without cobalt interference at potentials as cathodic as –1.0 V despite high Co concentrations. At more negative potentials, both metals are deposited simultaneously, although the copper proportion in the binary mixture is greater than that corresponding to the solution concentration ratio. Voltammetry studies effected under conditions in which codeposition occurs show only minor changes in copper behaviour. On the other hand, cobalt behaviour exhibits significant modifications. Even though formation of an intermetallic compound is possible, ASVL and microscopy tests indicate cobalt deposition in different crystalline forms as the more probable cause. In turn, cobalt deposition depends on the polarization conditions of the electrode and on the cobalt and copper concentrations. 相似文献
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四种方法对LDPE片材的表面改性与粘结 总被引:2,自引:0,他引:2
本文采用四种方法对LDPE片材进行表面改性,通过粘结强度(σ)的比较,讨论表面改性的结果,同时对不同方法的应用进行分析. 相似文献
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新一代磷酸锌系防锈颜料--磷酸铝锌的合成和应用 总被引:1,自引:0,他引:1
采用磷酸、氢氧化铝、氧化锌为原料,利用共沉淀直接法合成新一代磷酸锌系防锈颜料——磷酸铝锌,并对产品的防锈性能进行了初步的探讨和研究。实验结果显示其防锈性能及成本优于传统的磷酸锌。 相似文献
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