Physical Chemistry Commons^™

An Electro-Driving High Efficiency, Continuous, No-Damage Focusing Electrophoresis Concentration Device, Hua-Shui Lin, Liang-Ge Chen, Run-Xiang Zhang, Fan Luo, Wei-Ling Hu, Zhao-Wu Tian

Journal of Electrochemistry

We presented a membrane focusing concentration method and fabricatedan electro-driving high efficiency,continuous,no-damage focusing electrophoresis concentration device.In the concentration experiments of bromophenol blue and Na-fluorescein,the concentrated efficiencyof the device reached two orders of magnitude.This device can be magnified to industrial equipment with large output.It also can be miniaturized to small and simple attachment for separated and analytical instrument such as electrophoresis,chromatogram, mass spectrum and optical spectrum.When integrated into chips,it would be a pre-concentrated unit of the lab-on-chip.

An Electrochemical Investigation Of Methanol Crossover In Dmfcs, Meng-Di You, Xuan Cheng, Lian Liu, Lu Zhang

Journal of Electrochemistry

Methanol crossover and its effect on the open-circuit voltage(OCV) in DMFCs were studied usingcyclic voltammetry and chronoamperometry under stationary condition and at ambient temperature.An H-shapecell was constructed and a simulative DMFC test was carried out to investigate methanol crossover through Na-fion(117 from anode to cathode.The results revealed thatthe amountof methanol in the cathode side is depend-ent upon the time of penetration.As the concentration of methanol increased,the hydrogen adsorption-desorptionon the surface of electrode was suppressed and a shoulder peak appeared during the forward sweep for methanoloxidation.The simulative DMFC test also showed that the methanol crossover caused a sudden decline in theOCV.

Investigation On Ru-Ti-Ir Anode Coatings Modified By Adding Sn Element, Ke Wang, Yan Han, Jun-Tao Wang, Xiao-Ling Zhang, Yu-Pu Sun

Journal of Electrochemistry

The anode coatings of Ru-Ti-Ir-Sn oxide with various Sn contents were prepared by thermal decomposition and characterized by the scanning electron microscopy(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD),and the potential of chlorine evolution,current efficiency,cyclic voltammetry and electrochemical impedance spectroscopy(EIS).The results tests showed that there was a great change in the morphology of the coatings after adding Sn element.The addition of Sn not only reduced the potential of chlorine evolution,but also effectively improved the current efficiency of the anode coatings.

Compare Of The Behavior Of Different Sloth Filler Bipolar Packed Bed Cell In The Treatment Of Sodium P-Nitro-Phenolate, Shi-Yuan Guo, Ai-Li Zhang, Ji-Ti Zhou

Journal of Electrochemistry

Making use of sulphonated coal,fruit hull,plastic of PVC,old plastic in recovery,four kinds of sloth fillers which densities are equal to active carbon to substitute quartz sand which are applied in project extensively.And link with appropriate backwashing to resolve the problem of electrodes pollution and &lamination of the fillers in the bipolar packed bed cell.Then via the treatment of the waste water that contains sodium p-ni-tro-phenolate to investigate the possibility of application.The results are as follow.There are better resuk for the reactors packed with old plastics in recovery and sulphonated coal than the one filled with quartz sand,and the results of …

Electrochemical Impedance Spectrum Of Ferrocene At A Rotating Disk Glassy Carbon Electrode And Its Interaction With Dna, Can-Hui Chen, Hong Li, Jian-Zhang Zhou, Zhong-Hua Lin, Wei Zhu, Quan-Xin Zhang

Journal of Electrochemistry

The electrochemical impedance spectrum(EIS) of ferrocene(Fc) at a rotating glassy carbon(GC) electrode and its interaction with calf thymus DNA in Tris-NaCl buffer solution(pH=7.2) have been investigated by using electrochemical techniques such as rotating disk electrode(RDE),EIS and its data fitting.A plateau of the limiting current for the voltammetric curve and two capacitance arches obtained at the rotating GC electrode are exhibited.The interaction of Fc with DNA is represented by the decrease of limiting diffusion current and the increase of electrochemical reaction resistances with the increase of DNA concentration,respectively.On the other hand,based on the theoretical analysis and data fitting of RDE and …

Structure And Properties Of Electrodeposited Sn-Co Alloy Electrodes As Anode Material For Lithium-Ion Secondary Batteries, Hong-Hong Jiang, Ling Huang, Shun-Wei Zhou, Fu-Sheng Ke, Fang-Zu Yang, Xiao-Yong Fan, Shi-Gang Sun

Journal of Electrochemistry

The Sn-Co alloy deposits were prepared by electroplating.The structure and electrochemical performance of the electroplated Sn-Co alloys have been investigated in detail. Experimental results show that the porous Sn-Co alloy film exhibits hexagonal solid solution,with Sn as the solvent, Co as the solute. The texture of the Sn-Co alloy coating exhibits(110) preferred orientation. Electrochemical tests show that the porous Sn-Co alloy coating electrodes can deliver a discharge capacity of 643mAh/g in the first cycle. At the 20^h cycle the charge was 461mAh/g. At initial charge curve the irreversible capacity is probably associated to a combination of processes, which may …

High Density Lifepo4/C Synthesized By Controlled Crystallization And Microwave Carbon Thermal Reduction, Chang-Ping Tang, Jie-Rong Ying, Min Lei, Wei Li, Chang-Yin Jiang, Chun-Rong Wan

Journal of Electrochemistry

The spherical FePO₄·xH₂O was prepared in the solution by controlled crystallization.The precursor FePO₄ was obtained in high temperatureceramic approach,then the high density LiFePO₄ /C was synthesized by microwave carbon thermal reduction.The structure and morphology of the materials were characterized by means of XRD and SEM techniques,and the electrochemical properties were studies by charge-discharge experiments.

Effect Of Cracks On Corrosion Of Rebar In Concrete Studied By Wire Beam Electrode, Guo-Xi Li, Xian-Lu Hou, Ri-Long Zhu, Jin-Feng Hu, Yan-Na Du

Journal of Electrochemistry

The effects of crack and ethanolamine on corrosion of rebar in concrete were studied by measuring the distribution of corrosion potential and polarization resistance of iron wires in 10% NaCl solution.The results showed that the diffusion of water,oxygen and chloric ion toward concrete was accelerated by the crack which intensified the nonuniform corrosion of iron wire with the regions near to crack as anode and the uncracked regions as cathode.Ethanolamine could diffuse into the body of concrete and absorb on the surface of iron wire,which reduced iron corrosion evidently and successfully inhibited the nonuniform corrosion caused by crack without changing …

Tyrosinase Immobilizarion On Boron-Doped Diamond Electrodes And The Determination Of Phenolic Compounds, Yan-Li Zhou, Jin-Fang Zhi

Journal of Electrochemistry

As-grown BDD surfaces were first functionalized by photochemically linking vinyl groups of allylamine,producing covalently linked amine-terminated active BDD surfaces.Then the tyrosinase was immobilized onto the BDD surface through peptide linking.Cyclic voltammograms of phenol,pcresol and hydroquinone were measured using the tyrosinase-modified BDD electrode and amperometric characteristics such as sensitivity,linear response range and stability were studied.

Electrochemical Studies On Electrocatalytic Activity Of AuCore PtShell Nanoparticles To Methanol Oxidation, Fang Bao, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

Au_corePt_shell nanoparticles with different thicknesses were prepared by using chemical reduction method,and characterized by ultraviolet-visible spectroscopy(UV-Vis),transmission electron microscopy(TEM) and cyclic voltammetry(CV).The electrocatalytic activity of Au_corePt_shell nanoparticles with the mean diameter of 70~80 nm to methanol oxidation was investigated by cyclic voltammetry in the acid solution.The results revealed that the prepared core-shell nanoparticles were covered by Pt shell and exhibited the similar optical property and electrocatalytic activity with the normal Pt surface.Moreover,the electrocatalytic activity increased with the electrochemical sweep in the certain potential range.It might be contributed by the special loose structure of Pt shell …

Effects Of Eelectrolyte Salt To The Sei Layer Of Licoo2 Material, Ming-Sen Zheng, Quan-Feng Dong, Ya-Wei Zhu, Ya-Ding Zhan, Zu-Geng Lin

Journal of Electrochemistry

The character of the solid electrolyte interface (SEI layer) on the surface of LiCoO₂ formed in the electrolytes contained different salt such as LiPF₆, LiClO₄ and LiBF₄ were studied in this paper. The results showed that the SEI film exists in all three electrolytes after the processes of charge and discharge. The morphological character and the formation voltage of the SEI layer of LiCoO₂ were different in different electrolytes. The electrochemical performance of the battery such as reversible capacity, average discharge voltage and electrochemical impedance were affected significantly by SEI film formed in different …

Electrochemical Preparation Of Gd-Ni Alloy Film In Acetamide-Urea-Nabr Melt, Bi-Qing Chen, Jian-Chao Wang, Chen-Yu Guo, Jin-Gui Wang, Qing Liu

Journal of Electrochemistry

Cyclic voltammetry was used to study the electroreduction of Ni²⁺ to Ni on Pt and Cu electrode in acetamide-urea-NaBr melt at 353K.It is irreversible in one step.At Pt and Cu eletrode the diffusion coefficient and electron transfer coefficient of Ni²⁺ in 0.063mol/dm³) NiCl₂-acetamide-urea-NaBr melt were determined.The transfer coefficient α=0.28 and diffusion coefficient D_(0)=4.63×10^-5 cm²·s^-1 of the Pt eletrode and transfer coefficient α=0.22 and diffusion coefficient D_(0)=6.05×10^-7 cm²·s^-1 of the Cu eletrode were measured.It was put emphasis on that Gd³⁺ is not reduced to Gd alone …

Study On Composite Organic Inhibitor Of Zinc Electrode In Alkaline Solutions, Xue-Tao Bu, Guang-Chuan Liang, Cui Li

Journal of Electrochemistry

The synergetic influence of sodium dodecyl benzene sulfonate(SDBS) with Tween-20(Tween) on zinc electrode was studied by polarization experiment,surface tension test,discharge test and SEM.It is found that the composite inhibitor ST has a much higher efficiency.The addition of Tween reduced the critical micell concentration of SDBS on zinc electrode remarkably and the distribution of adsorption became more homogeneous.ST inhibits corrosion of zinc electrode and improves discharge capacity of the whole battery.Through electrochemical morphological observation of anodic passivation behaviors of zinc electrode,the absorption of ST on electrode surface makes discharged production much smaller and keeps crude porous structure intact.Passivation of zinc electrode …

Criticality Studies Of Dilute Plutonium Mixtures For Urex Processes, Denis Beller

Separations Campaign (TRP)

The completion of criticality experiments for mixtures of higher actinides (HA, includes neptunium, plutonium, americium, and curium) that will be created during the separation of used nuclear fuel has been identified as a requirement to construct prototype plants such as the Engineering-Scale Demonstration (ESD) and the Advanced Fuel Cycle Facility (AFCF) for the Global Nuclear Energy Partnership (GNEP). GNEP is a program to develop a worldwide consensus to enable the expanded use of economical, environmental nuclear energy to meet growing electricity demand. In this program and the Advanced Fuel Cycle R&D program (AFC) that supports it, we are developing economic …

Secondary N-Nitrosocarbamate Anions: Structure And Alkylation Reactions. A Dft Study, Vladimir Benin

Chemistry Faculty Publications

The current article reports theoretical studies (DFT: B3LYP/6-31+G(d)) on the structure and alkylation reactions of the anions of some secondary N-nitrosocarbamates, a class of ambident nucleophiles whose chemistry has been little explored. Several anions (1–4), with an increasing size of the carbamate alkyl (aryl) group were investigated, in an attempt to establish the influence of the size of that group on the thermal stability and regioselectivity of alkylation of the title anions. The conclusion is that thermal stability and the mode of reaction are affected significantly only in the presence of very large and branched carbamate groups. The thermal …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quaterly Report January-March 2006, Spencer M. Steinberg

Separations Campaign (TRP)

Project Highlights:

• Established that iodide can be oxidized by MnO₂ to I₂ at pHs of 4-8 and moderate temperature.

• Demonstrated that p-hydroxybenzoic acid can be iodinated by MnO₂ and KI at pHs of 2-8.

• Established that humic acids can be iodinated by MnO₂ and iodide at room temperature in pH range of 4-8.

Preparation Of Silica-Coated Lanthanum-Strontium Manganite Particles With Designable Curie Point, For Application In Hyperthermia Treatments, Vuk Uskoković, Aljoša Košak, Miha Drofenik

Pharmacy Faculty Articles and Research

Silica-coated lanthanum–strontium manganite particles with La_0.76Sr_0.24MnO_3+δ stoichiometric formula, exhibiting Curie temperature at ∼40°C, were prepared by using a traditional solid-state method of synthesis of magnetic ceramic particles, followed by milling and a low-temperature coating procedure in an aqueous alcoholic alkali medium. The properties of the obtained material establish it as a potential candidate for self-regulated power-absorbing and temperature-controlling materials in hyperthermia treatments. Moreover, core-comprising LaSr–manganites with different stoichiometries, ranging from La_0.5Sr_0.5MnO_3+δ to LaMnO_3+δ, were synthesized, with magnetic and structural properties examined thereof. Herein reported findings can potentially be …

Orientational Disorder In Sodium Cadmium Trifluoride Trihydrate, Nacdf3·3h2o, Robert W. Smith, Arthur Mar, Jianjun Liu, Stan Schnell, John R. Hardy

Chemistry Faculty Publications

Attempts to synthesize the hypothetical anhydrous fluoroperovskite NaCdF₃, which has been predicted to be stable, resulted instead in a hydrated fluoride of nominal composition NaCdF₃·3H₂O. It decomposes to sodium fluoride, cadmium fluoride, and water at 60 °C. Its structure has been determined by single-crystal X-ray diffraction. Na_0.92(2)Cd_1.08F_3.08·2.92H₂O crystallizes in the cubic space group with a = 8.2369(4) Å and Z = 4. The structure is based on the NaSbF₆-type (an ordered variant of the ReO₃-type) and features tilted sodium- and cadmium-centred octahedra …

The Electrochemical Separation Of Curium And Americium: Quaterly Report January - March, 2006, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This research report outlines the current status and progress associated with the electrochemical separation of Curium and Americium. For two and a half years, research has been actively performed on this project, and is currently on schedule for the proposed timelines.

Progress:

• The electrochemical characterization of Ce and Eu complexed with EDTA, NTA, and Citrate has been completed.

• Synthesis of the polymer substrate and the chelating ligand is underway. Approximately 50 grams of disulfide has been produced to produce the chelating thiol group required for the last set of studies.

• Gold substrates have been prepared to perform …

Electroless Nickel Plating On Carbon Nanotube With Non-Palladium Activation Procedure, Guang-Hui Hu, Hui-Huang Wu, Fang-Zu Yang

Journal of Electrochemistry

A new procedure of surface activation without using palladium salt was proposed for electroless nickel plating on carbon nanotubes.In the procedure,carbon nanotubes were oxidized by nitric acid and then neutralized with NaOH to create carboxyl surface groups which were used to adsorb Ni²⁺ ions,thereafter the adsorbed Ni²⁺ ions were chemically reduced into Ni nano-particles as a catalytic center for electroless nickel deposition,all these were further confirmed by infrared absorption spectra and electron microscopic observations.The results indicate that the procedure is feasible to electroless nickel plating on carbon nanotubes.The different morphology of deposits obtained from electroless plating was also …

Conductivity Of Comb Polyether Pure Solid Polymer Electrolyte, Lin Ye, Peng Gao, Zeng-Guo Feng, Feng Wu, Shi Chen, Guo-Qing Wang

Journal of Electrochemistry

A comb polymer was synthesized through cationic ring-opening polymerization starting from a monomer 3-hydroxymethyl-3-methyl-oxetane.The ion conductivity was measured by CHI660A electrochemical station under various lithium salt concentrations and various temperatures.The highest ion conductivity was recorded to be 10^-4.43 S/cm at room temperature and 10^-3.44 S/cm at 80 ℃.DSC results showed that the segment moves more difficultly with the increasing of lithium salts concentration.XPS found the existence of aggregating lithium ions in POE5 and POE10,and it suggested that POE20 had a suitable lithium concentration for polymer electrolyte.

Electro-Generated Feo42- Using Modified Chitosan Cation Exchange Membrane, Huai-Zhen Zhong, Ri-Yao Chen, Xi Zheng, Zhen Chen

Journal of Electrochemistry

The chitosan cation membrane was prepared by crosslinked 2% and doped with 1% H₂SO₄.The products were marked as MCS.The physical properties and the ion exchange capacity of MCS were studied.Compared to the non-modified membrane,it was found that chemical modifications contributed to improving ion exchange capacity from 0.25 to 2.09 meq/g.Results was also suggested that the MCS can be used as a separator when producing sodium ferrate flocculent using electrochemical process.

Studies On Pva-Cmc-Koh-H2O Alkaline Polymer Electrolytes, An-Bao Yuan, Jun Zhao

Journal of Electrochemistry

A given amount of sodium carboxymethyl cellulose(CMC)was added to PVA complex and thus the PVA-CMC-KOH-H₂O alkaline polymer electrolyte with this modification was prepared.The properties of the polymer electrolyte films were characterized by AC impedance,cyclic voltammetry,differential thermal analysis and infrared spectroscopic analysis methods.The polymer electrolyte exhibited a high ionic conductivity,typically 10^-2S·cm^-1 with an electrochemical stability window of about 1.6 V on stainless steel blocking electrodes.The influence of the film composition such as KOH,H₂O and CMC on ion conductivity was investigated.In addition,a preliminary study was carried out on the polymer electrolyte for Ni/MH battery.It was …

Anodic Behaviors Of Pb-Ca-Sn-Re Alloy And Tradditional Pb-Ca-Sn Alloy In Sulfuric Acid Solutions, Dang-Guo Li, Gen-Shu Zhou, Liang Yao, Guan-Fa Lin, Mao-Sheng Zheng

Journal of Electrochemistry

The anodic behaviors of Pb-Ca-Sn-Re and Pb-Ca-Sn alloys were investigated at 1.28 V(vsHg/(H₂SO₄)) in 4.5 mol/L sulfuric acid solution by means of ac voltammetry,ac impedance and cyclic voltammetry.The results showed that the corrosion-resistance property of Pb-Ca-Sn-Re alloy is better than that of tradditional Pb-Ca-Sn alloy,the growth of Pb(Ⅱ) compounds was inhibited in the film of Pb-Ca-Sn-Re alloy,and the film impedance of Pb-Ca-Sn-Re alloy was decreased,indicating that the conductivity of the film was(increased),which is helpful to enhance the deep recycling property for lead acid battery.

Mechanism Of Self Discharge Performance Improvement In The Ni-Mh Batteries With Naoh Electrolyte, Xiao-Feng Li, Tong-Chi Xia, Hui-Chao Dong, Yan-Wei Wei

Journal of Electrochemistry

The self-discharge performance and charge efficiency at 60 ℃ for Ni-MH battery can be markedly enhanced by using NaOH electrolyte instead of KOH electrolyte.Both the results of electrochemical impedance spectroscopy and cyclic voltammetry tests indicate that the separation of H₂ from the negative electrode may be partly blocked in the former because of the change of the adsorption/desorption behavior of H on the surface of the negative electrode,thus results in an improvement of self-discharge performance of the battery.

2006 National Conference On Corrosion Electrochemistry And Measuring Methods, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Potential Distributions On External Tank Bottom Under Cathodic Protection Of Deep Well Anode, Yan-Xia Du, Guo-Zhong Zhang, Gang Liu

Journal of Electrochemistry

Potential distributions of deep well anodic electric field on external tank bottom were derived according to the basic law of electromagnetic field and the geometry characteristics of cathodic protection system.Making use of electric field superposition principle,considering the action of anodic and cathodic electric fields,the potential distributions on external tank bottom under the protection of deep well anode were studied.The calculated results were compared and agred well with the measured data.

Preparation Of Spinel Limn2O4 Cathode Materials For Li-Ion Batteries Based On Sol-Gel Process, Xiang-Ming He, Li Wang, Guo-Yun Zhang, Chang-Yin Jiang, Chun-Rong Wan

Journal of Electrochemistry

Spinel LiMn₂O₄ was prepared from CH₃COOLi·2H₂O,Mn(CH₃COO)₂ and adipic acid based on sol-gel process.XRD analysis showed that when the sintering temperature increased,the crystallinity increased,and the capacity also increased.However,its cycleability reached a maximum value at 750 ℃.The sintering duration also influenced on the capacity.The optimized performance was obtained when the sintering was carried out at 750 ℃ for 20 h.Under these conditions,as-prepared spinel LiMn₂O₄  presented the initial discharge capacity of 130 mAh·g^-1 and 125 mAh·g^-1 at 15^th cycle.

Electrochemistry And Structures Of Silicon Surface, Gregory X.Zhang

Journal of Electrochemistry

Accurate control and fabrication of silicon surface structures from atomic scale to micrometer scale,which may be randomly associated with surface roughness or have well defined patterns,is critical for the per-formance and reliability of electronic devices.Electrochemical reactions of silicon in solutions involved in wetcleaning and etching of silicon wafer play an importantrole in determining the structures of silicon surface.Atre-mendous amount of researches have been done in the last several decades to understand and control a range ofcomplex electrochemical reactions at silicon/solution interface and their relations to the resulted surface struc-tures.The findings generated from these research efforts have been compiled and integrated …

Development On Hydriding/Dehydriding Kinetics Of Mg Nano-Materials For Hydrogen Storage, Wei Mo, Hong-Liang Sun, Hai-Chang Zhang, Hua-Bin Yang, Zuo-Xiang Zhou

Journal of Electrochemistry

The development of Mg nano-materials for hydrogen storage in the recent decade has been reviewed in this paper.It was shown the Mg nano-powders prepared by high-energy ball milling showed promising hydriding and dehydriding performance with the transition metal oxides and other types of hydrogen storage alloys(ABx)as the catalysts.