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Chinese Chemical Society | Xiamen University

Journal

1999

Articles 61 - 72 of 72

Full-Text Articles in Physical Sciences and Mathematics

Study Of Localized Corrosion Of Metals By Using The Electrochemical Techniques With Spatial Resolution, Changjian Lin, Xiangdong Zhuo, Zude Feng, Ronggui Du, Zhaowu Tian Feb 1999

Study Of Localized Corrosion Of Metals By Using The Electrochemical Techniques With Spatial Resolution, Changjian Lin, Xiangdong Zhuo, Zude Feng, Ronggui Du, Zhaowu Tian

Journal of Electrochemistry

The electrochemical inhomogeneities at interface of metal/solution play an important and often controlling role in localized corrosion of metals.The traditional electrochemical techniques involving potential,current density or ac impedance measurements over bulk specimens can only provide average and general information of the interface. Thus, the development of in situ imaging techniques is essential for further characterizing electrochemical inhomogeneities at the metal/solution interface of localized corrosion system.The electrochemical techniques with spatial resolution,including scanning single micro electrode,scanning double micro electrodse and scanning micro chemical probes are reviewed.The effects of electrochemical inhomogeneities on the corrosion behavior,and the mechanism fot various localized corrosion of metals …

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Electrochemical Surface Characterization Of Titanium Alloy(Ti_6al_4v)), Jianzhong Chen, Qingliang Gao, Zhongyi Wang, Wenjing Xue Feb 1999

Electrochemical Surface Characterization Of Titanium Alloy(Ti_6al_4v)), Jianzhong Chen, Qingliang Gao, Zhongyi Wang, Wenjing Xue

Journal of Electrochemistry

With its low density and high strength ratio, titanium alloy(Ti_6Al_4V) has become one of the most important materials both in the fields of aerospace and biomedical assays. Recently, titanium alloy was used as the implantation materials in human body because of its biocompatibility. The elecrochemical impedance techniques were then used to investigate the corrosion behavior of this material in hydrochloride and sulfuric acid solutions. A comparison between impedance spectra and anodic polarization over the correlated range of applied voltage confirms that AC impedance data can be used as a powerful tool for surface characterization of titanium alloy.

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Study On The Mechanism Of Ni/Zro 2 Composite Electrodeposition, Qunjia Peng, Daobin Mu, Jusheng Ma, Xiangyun Tang Feb 1999

Study On The Mechanism Of Ni/Zro 2 Composite Electrodeposition, Qunjia Peng, Daobin Mu, Jusheng Ma, Xiangyun Tang

Journal of Electrochemistry

The effects of cathodic current density and amount of particle dispersion in solution on the codeposition of Ni/ZrO 2 composite in Watts bath were studied, and the machanism of the composite electrodeposition was investigated.The study shows that the composite electrodeposition is controlled by the transfer of particles to the cathode when the dispersion amount is small, causing the decrease of the codeposition with the increase of current density. With large amount dispersion,the composite electrodeposition is first controlled by the strong adsorption of particles on the cathode at low current density, resulting in the increase of the codeposition with the increase …

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Electrodeposition Of Neodymium_Iron Group Alloy Films In( P _Ch 3c 6h 4so 3) 3nd+Dmf System, Peng Liu, Yexiang Tong, Qiqin Yang, Yansheng Yang Feb 1999

Electrodeposition Of Neodymium_Iron Group Alloy Films In( P _Ch 3c 6h 4so 3) 3nd+Dmf System, Peng Liu, Yexiang Tong, Qiqin Yang, Yansheng Yang

Journal of Electrochemistry

Neodymium p _toluenesulfonate was prepared and applied to the electrodepositon of neodymium_iron group alloy films. This salt has high solubility in DMF and can be dehydrated easily. Cyclic voltammograms of Pt electrode in ( p _CH 3C 6H 4SO 3) 3Nd+MCl 2(M=Fe,Co,Ni)+DMF indicated that the neodymiun_iron group alloys can be elcetrodeposited from this medium, the Nd_Fe,Nd_Co and Nd_Ni films were obtained by electrolysis at constant potential. The Nd_Fe,Nd_Co and Nd_Ni films are amorphous in which the rare earth contents are in the range of 15 at%～60 at% as analyzed by XRD and EDS. The Nd content in the deposited film …

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Pitting Corrosion Of Ni_Based Alloy In Thiosulfate_Ion Containing Chloride Solutions, Yungfa Lee, Tingyu Wang, Wenta Tsai Feb 1999

Pitting Corrosion Of Ni_Based Alloy In Thiosulfate_Ion Containing Chloride Solutions, Yungfa Lee, Tingyu Wang, Wenta Tsai

Journal of Electrochemistry

The effect of thiosulfate ion on the pitting corrosion behavior of Ni_Based Alloy 690 in chloride solution was investigated.In plain sodium thiosulfate solution,Alloy 690 was immune to pitting corrosion. However, the addition of low concentration of sodium thiosulfate can enhance the initiation of pitting corrosion of Alloy 690. Nevertheless, inhibition of pitting corrosion was observed at high concentration of addition.

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Synthesis And Application Of Polymeric Corrosion Inhibitor For Reinforced Concrete, Weiwei Lin, Shengxian Wang, Jianqing Zhang Feb 1999

Synthesis And Application Of Polymeric Corrosion Inhibitor For Reinforced Concrete, Weiwei Lin, Shengxian Wang, Jianqing Zhang

Journal of Electrochemistry

A new polymer E Twas synthesized and used as a corrosion inhibitor for reinforced concrete. The inhibitive behavior and mechanism were studied with linear polarization ,Tafel polarization,EIS and XPS method in simulated pore solution system with concrete samples.The result showed that the polymer was a mixing type inhibitor. A 1% dosage was sufficient to imhibit the corrosion of steel in simulated pore solution system. The salt endurance was enhanced from 0.02 mol/L to 0.10 mol/L.The result also showed the good synergetic effect of NaNO 2,especially in low NaNO 2 concentration.The EIS showed that E_T has dual function on reinforced concrete,i.e.,densifying …

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Study On Steel Corrosion In Simulated Biofilm Environment In Seawater, Qingfei Wang, Jing Sui, Runxi Su, Deying Kong, Shizhe Song Feb 1999

Study On Steel Corrosion In Simulated Biofilm Environment In Seawater, Qingfei Wang, Jing Sui, Runxi Su, Deying Kong, Shizhe Song

Journal of Electrochemistry

Biofilm is one of the main factors that influence metal corrosion in seawater environment. According to the structure and property of biofilm, a natural biopolymeric gel,calcium alginate(an extracellular biopolymer containing carboxylate functional groups) can deposite on metal surfaces to form films. Corrosion behavior of alloyed steel E 2, 10CrMoAl and 18_8 stainless steel were studied in simulated biofilm environment by various electrochemical methods,including measurements of the corrosion potential,polarization curves,galvanic current and electrochemical impedance.The results show that such an approach is informative to reveal “how” and “to what extent” biofilm can influence the metal corrosion process.

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Structural And Electrochemical Studies On Todorokite/Vernadite As Cathodes For Rechargeable Lithium Ion Batteries, Wei Chu, Deyao Liu, Jinkua You, Yong Yang, Zugeng Lin Feb 1999

Structural And Electrochemical Studies On Todorokite/Vernadite As Cathodes For Rechargeable Lithium Ion Batteries, Wei Chu, Deyao Liu, Jinkua You, Yong Yang, Zugeng Lin

Journal of Electrochemistry

XRD,TEM,ICP,low scan_rate CV and charge/discharge tests were carried out for the studies on the structural and electrochemical behavior of a prepared 3 V manganese oxide cathode for rechargeable lithium ion batteries.XRD analysis revealed that the cathode sample is mainly composed of tunneled Todorokite and layered Vernadite.TEM investigation confirmed that the morphology of the sample is a laminated construction with approximate 10nm layer space.The reversibility of Li + removal/intercalation and structural stability of this sample framework to lithium insertion are good in CV and charge/discharge tests. The discharge capacities were found to be about 129mAh/g obtained on first 30 cycles and …

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Study Of Electrochemistry Of Tetrasulphonated Phthalocyanine Zinc In Aqueous And Nonaqueous Solvents, Ersheng Liu, Yiqun Wu, Jianhui Yang, Liying Huang, Jundong Wang, Suling Yang, Naisheng Chen, Jinling Huang Feb 1999

Study Of Electrochemistry Of Tetrasulphonated Phthalocyanine Zinc In Aqueous And Nonaqueous Solvents, Ersheng Liu, Yiqun Wu, Jianhui Yang, Liying Huang, Jundong Wang, Suling Yang, Naisheng Chen, Jinling Huang

Journal of Electrochemistry

The voltammetry of Tetra_sulphonated phthalocyanine Zn(TSPcZn)in DMSO and DMF solution has been examined and compared with those obtained in aqueous solution.The results showed that three pairs of redox peaks were appear in non_aqueous solvents,exhibiting three quasi_reversible phthalocyanine ligand based one_electron transfers,while in aqueous solution did no quasi_reversible behaviour was observed. The photoelectrochemical effect of light on TSPcZn redox reactions were also discussed.

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Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xianyou Wang, Yunshi Zhang, Jie Yan, Zheng Zhu, Huatang Yuan, Deying Song Feb 1999

Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xianyou Wang, Yunshi Zhang, Jie Yan, Zheng Zhu, Huatang Yuan, Deying Song

Journal of Electrochemistry

The surface of the spherical nickel hydroxide particles used as an active material in pasted nickel electrodes is surface_deposited with cobalt. This paper investigated the effects of the amount of cobalt deposit on the characteristics of nickel hydroxide electrode. The performances of the electrode, such as discharge capacity, utilization of active material and reversibility of Ni(OH) 2/NiOOH redox reaction, were studied by comparing the charging/discharging curves and cyclic voltammograms. The mechanism of action of cobalt deposits has been described in terms of the electrochemical impedance spectroscopy of nickel hydroxide electrode.

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Study On Ionic Conductivity Of A Novel Solid State Electrolyte, Yingxin Zhao, Changyan Liu Feb 1999

Study On Ionic Conductivity Of A Novel Solid State Electrolyte, Yingxin Zhao, Changyan Liu

Journal of Electrochemistry

Various novel predominantly lithium_ion_conducting solid state electrolytes were described, which had high conductivity at room temperature. It comprised low_melting_point eutectic lithium salts in which a small amount of an single ion polyeletrolyte poly(lithium acrylate) was dissolved to rubberize them. The effects of the eutectic and polymer features upon the ionic conductivity were discussed.

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Electrohydrodimerization Of Fumarodinitrile On Liquid Gallium Electrode, He Wei, Huang Ying Feb 1999

Electrohydrodimerization Of Fumarodinitrile On Liquid Gallium Electrode, He Wei, Huang Ying

Journal of Electrochemistry

Electrohydrodimerization(EHD) of fumarodinitrile on liquid gallium electrode can take place not only in hydrotropic solution of tetraethylammonium p_toluenesulphonate(TEA_PTS), but also in aqueous solution containing low concentration of strong surfactants, such as TritonX_100. In solution without organic surfactant, FDN yields a single two_electron reduction wave corresponding to the formation of a saturated monomer called as butanedinitrile. If some TEA_PTS or TritonX_100 is added into the solution, the original two_electron wave is splitted into two continuous single_electron reduction wave and corresponding EHD of fumarodinitrile is obtained.

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