Chemistry Commons^™

Preparation And Electrochemical Preformance Of Zn-La Alloys, Xian-Ling Meng, Hua-Bin Yang, En-Dong Yang, Xiao-Dan Wang, Hai-Chang Zhang, Jun-Hong Wang, Zuo-Xiang Zhou

Journal of Electrochemistry

Zn-La alloys were prepared by solid phase diffusion method and the effects of La on the electrochemical performance of zinc electrodes were investigated using potentiostatic polarization technique and charging/discharging cycle test. The results showed that adding La to zinc electrode remarkably suppressed the zinc dendrite, the shape of zinc electrode and zinc corrosion, and hence, markedly improved the cycle performance of zinc electrodes. The discharging capacity of the zinc electrode containing 0.5at.% La which was the optimum was still 520 mAh/g after it cycled 80s at the current of 100 mA. The XPS showed that La element mainly adhered on …

Synthesis And Electrochemical Characteristics Of Nickel-Based Complex Oxide LiANi0.78Co0.2Cd0.02O2, Rong-Zhong Yuan, Mei-Zhen Qu, Zuo-Long Yu

Journal of Electrochemistry

The nickel-based complex oxide Li_aNi_0.78Co_0.02O₂ cathode materials for lithium-ion rechargeable batteries was synthesized by the improved solid-state reaction method with LiOH·H₂O, ball-like Cd-doped Ni(OH)₂ and Co₂O₃ as raw materials. The analysis ICP-AES proved that the as-prepared compounds were near the stoichiometric form. The XRD, SEM and electrochemical characteristics testing were also carried out. The results showed that the complex cathode material Li_aNi_0.78Co_0.2Cd_0.02O₂ has layered structure, homogeneous surface distributions,uniform particles with good crystal morphology as well as stable electrochemical …

Perfluorinated Sulfonic Acid Lithium Conductivity Humidity Sensor, Hong-Feng Xu, Jing Liu, Li Wan

Journal of Electrochemistry

Treat carbon paper with 3% PTFE solution and dried in 340 ℃ for 40 minutes to enhance its intension, and level off the surface of the carbon paper with a mixture of XC-72 carbon black and PTFE solution. With those treated carbon paper as electrodes, recast Nafion thin film from 5% Nafion solution as humidity sensitive material, a solid polymer electrolyte humidity sensor was prepared on a thin PET film. Take the relative humidity data from several saturated salt solutions, the relationship between conductivity response and relative humidity was studied at different relative humidies .The results showed: when the polymer …

Conductance Properties For Electrolyte Of Lithium Ion Battery At Low Temperature, Jing-Li Han, Yan-Mei Yu, Jian Chen, Chun-Tong Wang

Journal of Electrochemistry

The system of LiPF₆-ethylene carbonate (EC)-methy1 acetate (MA) was studied. The conductivities of this system were measured under various composition and various salt concentrations at temperature range of 20～-50 ℃. The optimum composition of this system was selected. The tests of cyclic voltammography and charge-discharge were carried out. This system was compared with commercial electrolyte solution.

Effect Of Scn- On The Transition Current Of Zn During The Electrodeposition Zn-Co Alloys, Ren-He Yin, Wei-Min Cao, Zheng-Hua Fang

Journal of Electrochemistry

For co-deposition of Zn-Co alloys at sufphate baths with micro-concentration of SCN^- the transition current of Zn was found with the deposition process changing from normal Co-deposition to anomalous co-deposition, and the value of transition current increased with increasing SCN^- concentration, but decreased with increasing value of pH. The existence of SCN^- decreases the evolution overpotential of Co metal, but has no effects on the evolution overpotential of Zn metal and H₂.

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Randy Clarksean

Separations Campaign (TRP)

Two activities are proposed: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model will be continuously focusing on the integrated approach to the analysis of the materials separations associated with the TRP Program. A second portion of the project will streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to the systems engineering model. …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral …

Solvent And Method For Extraction Of Triglyceride Rich Oil, Shubhender Kapila, Paul Ki-Souk Nam, V. J. Flanigan

Chemistry Faculty Research & Creative Works

The present invention relates to a solvent for use in extracting oil from an oil bearing material, such as soybeans, with the solvent resulting in the selective extraction of a triglyceride rich oil, which contains 95% or greater triglycerides and non-polar constituents, with the solvent comprised of a hydrocarbon, preferably hexane, and a fluorocarbon, so that the solvent has a viscosity less than 2.6 centipoise and a polarity of less than 0.1. The present invention also relates to a method of using the solvent to extract the triglyceride rich oil, with the method including preferably extracting the oil at a …

Stress Corrosion Cracking Of Type 422 Stainless Steel For Applications In Spallation-Neutron-Target Systems, Ramprashad Prabhakaran

Transmutation Sciences Materials (TRP)

Introduction

• This research program is aimed at evaluating different types of environment-induced degradation of candidate target materials for applications in transmutation of spent nuclear fuels (SNF).

• Transmutation refers to the elimination of long-lived actinides and fission products from SNF.

Objectives

• Evaluate susceptibility of candidate target materials to stress corrosion cracking (SCC) and localized corrosion (pitting and crevice) in neutral and acidic aqueous environments at ambient and elevated temperatures

• Determine the extent and morphology of cracking in tested materials as functions of experimental and environmental variables including pH, temperature, loading conditions and specimen geometry

• Develop mechanistic …

Dynamics Of Adsorbed Poly(Methyl Acrylate) And Poly(Methyl Methacrylate) On Silica, Frank D. Blum, Wuu-Yung Lin, Crystal E. Porter

Chemistry Faculty Research & Creative Works

Deuterium NMR and modulated differential scanning calorimetry (MDSC) were used to probe the behavior of ultrathin adsorbed poly(methyl acrylate) (PMA). The spectra for the bulk methyl-labeled PMA-d3 were consistent with the motions of the polymer segments being spatially homogeneous. For the polymers adsorbed on silica, multicomponent line shapes were observed. The segmental mobility of the surface polymers increased with increased adsorbed amounts. In contrast to the behavior of the polymers in bulk, the adsorbed lower-molecular-mass PMA-d3 was less mobile than the adsorbed high-molecular-mass polymer. The presence of a polymer overlayer was sufficient to suppress the enhanced mobility of the more-mobile …

Density Of States Simulations Of Proteins, Nitin Rathore, Thomas A. Knotts Iv, Juan J. De Pablo

Faculty Publications

A modified version of a recently introduced algorithm that calculates density of states by performing a random walk in energy space has been proposed and implemented to study protein folding in a continuum. A united atom representation and the CHARMM19 [B. R. Brooks, R. E. Bruccoleri, B. D. Olafson, D. J. States, S. Swaminathan, and M. Karplus, J. Comput. Chem. 4, 187 (1983)] force field are employed for these simulations. This method permits estimation of the density of states of a protein via a random walk in the energy space, thereby allowing the system to escape from local free-energy minima …

Magnetic Resonance Studies On Lithium Intercalation Into Carbons, Xiao-Rong Zhou, Zhen-Ming Du, Lin Zhuang, Jun-Tao Lu

Journal of Electrochemistry

The electron spin resonance(ESR) and 7Li-NMR magnetic resonance (7Li-NMR) studies on lithium intercalation into carbons were reviewed based on recently published papers, including those by the authors of this review. Two kinds of electronic spins were found in ESR studies. One corresponds to the charge carrier electrons and is called the Pauli spin. From the ESR intensity of Pauli spins, the curve of the density of electronic states can be deduced for the carbon material studied and, in turn, the contribution of the band model mechanism to the lithium intercalation can be calculated for the given carbon sample. The other …

The Study On The Synthesis And Electrochemical Property Of K2Feo4, Yong-Long Wang, Ning Zhou, Shi-Hai Ye, Xue-Ping Gao, Feng Wu, Zuo-Xiang Zhou, De-Ying Song

Journal of Electrochemistry

The synthesis,characterization and electrochemical property of K₂FeO₄ for positive materal of lithium ion battery were studied. K₂FeO₄ with low purity was gained through the reaction of KCIO and Fe(NO₃)₃ in KOH solution and after recrystalization the purity of K₂FeO₄ reached 97%～98%. The methods of XRD and FTIR were used to measure the structure of K₂FeO₄ and its initial discharge performance was tested.

Study Of Electrochemical Lithium Intercalation Performance Of Ni0.67Mg0.33O, Zhen-Cai Huang, Mao-Hui Chen, Guo-Tao Wu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

In the present work, Ni_0.67Mg_0.33O and NiO were produced by sol-gel method, and characterized by XRD, a rietveld refinement and the discharge/charge test.It was found that the magnesium-doping restrained the reduction of Ni and decreased the reversible capacity for the sample of Ni_0.67Mg_0.33O. But the formation of the solid solution after the magnesium-doping facilitated the high dispersion of NiO, and accordingly improved the electrochemical performance.

Application Of Biphenyl Electroploymerization For Overcharge Protection In Li-Ion Batteries, Li-Fen Xiao, Xin-Ping Ai, Yu-Liang Cao, Han-Xi Yang

Journal of Electrochemistry

The electropolymerization of biphenyl at overcharged positive electrode was investigated for overcharge protection of Li-ion batteries. Biphenyl in electrolyte as an additive can electrochemically polymerize at 4.5～4.75 V(vs. Li/Li⁺) to form a layer of conductive film on cathode surface. The surface film increases the internal resistance and the gases released during the electropolymerization also increases the internal pressure of the batteries, which therefore enhance the sensitivities of the electrical disconnecting devices. During prolonged overcharge, the growth of the conductive polymer film can create short circuit between the positive and negative electrodes and cause self-discharge of the batteries to …

In Situ Measurements Of Solution Conductivity In Microwave Field, Yong-Qing Su, Chun-Peng Liu

Journal of Electrochemistry

The curves of the conductivity as a function of temperature for 24 kinds of solutions have been in situ measured both in the microwave field and in absence of microwave field. The results indicated that the relationship between the conductivity in microwave field (L_w) and temperature (T) can be expressed by an equation L_w=a′+b′T+c′T² , similar to the one that is valid in absence of the microwave field L_n=a+bT+cT². Conductivity in the absence and presence of microwave field can be linked by the equation lnL_w=A+BL_n+CL²_{n …}

An Eqcm Study Of Water Adsorption And Oxidation On Pt Electrodes In Sulfate Acid Sulotions, Heng Lin, Sheng-Pei Chen, Jin-Mei Lin, Ai-Lan Lin, Guo-Liang Chen

Journal of Electrochemistry

Simultaneous frequency and current responses during potential cycling of Pt electrode were measured in 0.1 mol·L^-1 H₂SO₄ solution by using EQCM. Quantitative analysis of the mass change revealed that the increase of mass in the hydrogen and double-layer regions in a positive-going potential scan was due to water adsorption on the Pt electrode, further calculation indicated that water molecules adsorbed on Pt electrode in the double-layer regions through a low discharge quomodo .The EQCM studies provided quantitative results of surface mass variation during water adsorption and oxidation,and have thrown new light in elucidating the structure of …

Behaviors Of Fe-Cr Alloys During Cavitation Damage, Xia Bai, Dong-Bai Sun, Hong-Ying Yu, Hui-Ming Meng, Hui-Qin Li, Zi-Shuang Fan

Journal of Electrochemistry

The influence of the surface galvanic effect on the behaviors of three Fe-Cr alloys during cavitation damage in NaCl solutions have been investigated. The results showed that the galvanic effect caused by the inhomogeneity between the undamaged surface of the alloy and the damaged one will be enhanced by the area ratio of the undamaged and the damaged. The behaviors of alloys during cavitation are closely related to both their mechanical performance and anti-corrosion capabilities.

Study For The Cathodic Behavior Of Active Chlorine On 316l Ss Electrode Surface, Hui Yu, Ming-Xian Sun, Yan Ma, Xiao-Bin Wang

Journal of Electrochemistry

The cathodic reducing reactions of active chlorine on 316 L SS electrode surface have been investigated by electrochemical techniques. The open circuit potential shifted positively and the limited diffusion current density increased significantly with the increasing content of active chlorine in the 3.5% sodium chloride solution. The two cathodic reduction processes of HClO and ClO^- exhibited on the surface of electrode with the active chlorine added to the 3.5%sodium chloride solution and the corresponding potentials of the two reducing reactions were confirmed. The linear relationship of the mass transport-limited Faradaic current, Id vs. the square root of the angular …

Development And Study Of The (Ag)-Ni/Cr Composite Plating With Antibacterial Properties And Corrosion Resistance, Ya-Ping Zhao, Jin-Hua Wang, Ren-He Yin, Jin Zheng, Le-Shu Yu

Journal of Electrochemistry

The 3-factor and 3-level orthogonal experiment was designed and through the comparison of the different films' antibacterial properties measured by bacterial colony counting and the corrosion resistance studied with the AC impedance method. The optimal plating conditions of the (Ag)-Ni/Cr composite plating, a novel functional plating, were determined. The results have indicated that the (Ag)-Ni/Cr composite plating is characterized by both antibacterial and corrosion resisting properties and has its wide applied prospect.

Investigations Of Smooth Function Of Polyethylene Glycol Surfactants On The Electrolessly Deposited Silver Film, Hao Tong, Zhi-Qing Qiao, Fen-Ning Jing, Meng-Ke Li, Chun-Ming Wang

Journal of Electrochemistry

Some non-ionic surfactants of Polyethylene Glycol 2000, 6000 and 20000 were used to estimate the smooth affection on the electrolessly deposited silver film. The adsorption state of the surfactants about Si/solution interface was investigated by using open circuit potential-time technology (Opt). As comparative experiments, the atomic force microscopy (AFM) was also performed to study the surface smooth effection of the surfactants. It was found that with the increasing of the carbon chain in the surfactants, the smooth effection is getting great. PEG 20000 showed the best smooth function.

Fenton Reagent Produced In Electrolysis Cell And Its Using In Degradation And Decolourization Of Dye, Xi Zheng, Ri-Yao Chen, Rui-Fang Lan, Xiao Chen, Zhen Chen

Journal of Electrochemistry

The electro-chemical processing to produce Fenton reagent has been described. Fenton reagent having a high redox potential has been used as an oxidant in treatment of dye wastewater. Results show that both of the degradation and decolourization of dyes are efficient. The decolourization of dye wastewater reaches 100%.The COD removing rate is about 80%.

Electroreduction Of Cd(Ⅱ) In Dmso And Complexation Of Cd(Ⅱ) With Coumarin Derivates, Ji-Guo Song, Hua-Can Song, Qi-Qin Yang, Yi-Wen Chen, Zun-Le Xu

Journal of Electrochemistry

Cadmium p-toluenesulfonate was synthesized and tested electrochemically for the first time. This salt can lose all the hydrated water easily and the dehydrated salt do not deliquesce in the air.Hence,the cadmium p-toluenesulfonate is suitable for the electrochemical studies in organic solvents.When the Cd(Ⅱ) reduced on Pt electrode in Cd(p-CH₃C₆H₄SO₃)₂+TBAP+DMSO, underpotential deposition of cadmium occurred at first, and then cadmium deposited. 4-Methyl-7-hydroxylcoumarin and 3-aminocoumarin coordinate with Cd(Ⅱ) respectively, as a result the reductive potentials of Cd(Ⅱ) moved to the negative direction.

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

During the past two years (2001-2002) of this project, the primary effort was focused on evaluating the effect of hydrogen on the cracking behavior of candidate target materials namely, Alloys EP-823, HT-9 and 422 in aqueous environments of different pH values at ambient and elevated temperatures. More recently, emphasis is being placed to evaluate the cracking behavior of these materials in molten lead-bismuth eutectic (LBE) environment at much higher testing temperatures so as to compare the cracking susceptibility in environments containing molten metals and aqueous solutions, respectively. The most recent tests to evaluate the cracking susceptibility were primarily based on …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report 12/1/02- 2/28/03, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the AAA proposed application.

Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with very limited density. The transport of oxygen and corrosion products, their interaction and variation of corrosion/precipitation along the flow are not well understood.

The first subtask of this project involves using a …

The Electrochemical Performance Studies On Novel Lifepo4 Cathode Materials For Li-Ion Batteries, Zhi-Cong Shi, Chen Li, Yong Yang

Journal of Electrochemistry

The cathode materials of LiFePO₄ and  LiFePO₄ coated with carbon were synthesized by means of solid state reaction and ballmilling. The samples were characterized by X-ray diffraction, scanning electron microscopy, gas-phase element analysis and titration analysis methods. Electrochemical tests of two kinds of materials showed that both of them exhibit a 3.4V discharge voltage plateau, however, the coated samples demonstrated the improved performance in terms of discharge capacity and cyclic stability.

The Preparation And Characterization Of Zno-Pani Composite Film, Yan-Yan Xi, Huai-Guo Huang, Zhi-Xin Zheng, Ping Dong, Jian-Zhang Zhou, Ling-Ling Wu, Zhong-Hua Lin

Journal of Electrochemistry

ZnO nanoparticle films were prepared on the Au film, PANI film and ITO by sol-gel method, and their morphological optical and photoelectrochemical properties were also studied. The results showed that the porous structure of PANI can suppress the aggregation of ZnO particles, resulting in the blue shift of on-set in the UV-Vis spectra and fluorescence spectra of ZnO-PANI composite film compared with that of ZnO-Au film. It was suggested that the ZnO-PANI composite film can be used in photoelectric coversion.

The Electrochemical Behavior Of Amorphous Ni-P And Ni-B Alloys In 0.5 Mol/L H2So4, Xu-Cheng Wang, Wei-Jiang Wang, Hou-Tian Liu, Zu-Zhan Yu

Journal of Electrochemistry

Polarization curves and impedance spectra were used to investigate the electrochemical behavior of amorphous Ni-P and Ni-B alloys in 0.5 mol/L H₂SO₄ solutions. The possible reason about the remarkable difference in the electrochemical behavior between amorphous Ni-P and Ni-B alloys was discussed.

Study On The Corrosion & Electrochemical Properties Of Alloy Aa5083 And The Effect Of Active Chlorine In Seawater, Hong-Ren Wang, Jian-Hua Wu, Jun-Tao Wang, Hong-Bin Wang, Zhi-Gang Fang

Journal of Electrochemistry

In this paper potentiodynamic technique, cyclic polarization technique and immersion corrosion method were used to study the corrosion and electrochemical properties of AA5083 alloy in quiescent seawater, the effect of active chlorine on its properties was also studied. The results obtained indicate that the active chlorine has no remarkable impact on the corrosion and electrochemical properties of AA5083 alloy in area of design concentration which range from 0.2 to 0.5 mg/L, and it has favorable influence on the improvement of pitting corrosion resistance. While the pH value of seawater has evident influence on the corrosion resistance of AA5083 alloy.

Synthesis By Complexation Processes And Characterization Of Lini0.8Co0.2O2 Cathode Materials, Jing Liu, Zhao-Yin Wen, Zhong-Hua Gu, Xiu-Jian Zhu, Zu-Xiang Lin

Journal of Electrochemistry

The layered LiNi_0.8Co_0.2O₂ compound, which has been of great interest for lithium ion batteries, was prepared at low temperatures by calcining a complex precursor at different temperatures. The physical properties of the synthesized cathode materials were discussed in the light of structural (XRD). The charge and discharge cycling of the cells containing the synthesized oxide as the positive electrode in conjunction with lithium metals and employing a non-aqueous electrolyte showed that LiNi_0.8Co_0.2O₂ treated at 900 ℃ exhibited excellent performances. The first discharge capacity of LLiNi_0.8Co_0.2O_{2 …}