Materials Science and Engineering Commons^™

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Final Report -Phase I 09/01/2001-08/30/2002, 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 only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Optimum Of Catalyst Layers For Direct Methanol Fuel Cells, Jun Zhang, Lei Li, Li Xu, Yu-Xin Wang

Journal of Electrochemistry

The performances of membrane electrode assemblies (MEAs)with various Pt loading were compared. The amount of Nafion in a catalytic layer was optimized, and the effect of Nafion loading on the resistance of MEAs was investigated with ac impedance spectroscopy. For a MEA with both Pt 4 mg/cm² in the anode and the cathode, suitable Nafion loading was 21.4 wt% in the anode. With 21.4 wt% Nafion loading in the cathode, the Direct Methanol Fuel Cells(DMFC) showed the highest performance at high current density. While, the DMFC performances came down, as Nafion loading increasing,for ohm and concentration polarization.

Electrochemical Properties Of Nitrate Immobilized On Gold Electrodes With 2-Aminoethanethiol Sams, Ya-Ru Song, Hong Wu, Hui-Bo Shao

Journal of Electrochemistry

Nitrate reductase (NR) and phospholipids were immobilized on gold electrodes with 2-aminoethanethio(AET) SAMs. After Au/AET/NR and Au/AET/NR/lipid were soaked in pH 7 phosphate buffers for days, a pair of pre-reversible peak appeared at around 0.202 V and 0.149 V respsctively, irregularly grew with soaking time in blank buffer.The cathodic peak current (i_pcl) of Au/AET/NR system had linear relationship with scan rate between 0.02 and 0.5 V⋅s^-1 ,while i_pcl was proportional to V^1/2 in Au/AET/NR/lipid system. The direct electron transfer of enzyme electrodes was strongly affected by pH. Compared with Au/AET, NR exhibited a higher electrochemical …

Diffusion Of Hydrogen At Iron Apply For Electrochemical Oscillating Permeation, Li Zhang, Ren-He Yin, Zhan-Mei Sun

Journal of Electrochemistry

The diffusion of hydrogen in iron was measured using electrochemical oscillating permeation. Through the samples in the different frequencies, it was found that diffusion of hydrogen at iron is of linear relation with boundary condition, which is the key to Fick's diffusion equation amplitude in the liquor. We can exploit this line relation getting the diffusion of hydrogen at iron.

Xrd Study On Highly Preferred Orientation Cu Electrodeposit, Min Gu, Fang-Zu Yang, Ling Huang, Shi-Bing Yao, Shao-Min Zhou

Journal of Electrochemistry

Copper electrodeposit was obtained in CuSO₄+H₂SO₄ electrolyte solution by electrodeposition and its structure was studied by XRD. The results showed that copper electoddeposits with the highly preferred orientations of (220) and (111) could be obtained at current density 4.0 A/dm² and 15.0 A/dm², respectively. The texture coefficient (TC) values were increased by thickness of Cu deposits. The thickness would be, to obtain Cu electrodeposit with (111) highly preferred orientation, about 7 times of that of (220) highly preferred orientation, which indicated that(220) face was easier to be remained than (111) face and …

Ionic Conduction In Ba0.95Ce0.9Y0.1O3 - Α Solid Oxide And Its Performance In Fuel Cell, Gui-Lin Ma, Ding-Xian Jia, Li-Gan Qiu, Hui Shi, Rong Chen

Journal of Electrochemistry

Using Ba_0.95Ce_0.9Y_0.1O_3-α as a solid electrolyte and porous platinum as electrodes,hydrogen and oxygen concentration cells and hydrogen-air fuel cell were constructed, respectively. Electromotive forces (MEFs) of the gas concentration cells and I-V characteristics of the fuel cell were detdrmined in the temperature range of 600～1 000 ℃. The Ba_0.95Ce_0.9Y_0.1O_3-α exhibited almost the pure protonic conduction under hydrogen gas,and a mixed conduction of oxide-ion and electron hole with oxide-ion transport number of 0.3～0.5 under oxygen gas. It exhibited a mixed conduction of proton and oxide-ion with the …

Modification Of Molybdenum Nitride Electrode For Supercapacitor(I)——The Effect Of Ammonium Vanadate On The Properties Of Molybdenum Nitride Electrode, Xue-Liang Li, Dao-Rong Luo, Hua-Lin Wang, Jian-Bo He, Yun-Guei Zhu

Journal of Electrochemistry

The effect of vanadium on the properties of the electrode of molybdenum nitride has been studied by using XRD, SEM and cyclic voltammetry. Modified molybdenum nitride was made as follow: films were coated by dipping titanium sheet in the solution containing different composition of molybdenum oxide, ammonium vanadate, ammonia, glycol and oxalic acid, and coated films are reacted with free ammonia. The results show that the specific capacitance of modified electrode was considerably increased and the operation voltage was broadened with the addition of ammonium vanadate in the dipping solution. The mechanism of these effects generated is the formation of …

Pure Hap Film Prepared By Direct Electrodepositing On Metallic Surface And Its Mechanism, Hao-Bing Hu, Chang-Jian Lin, Fei Chen, Ren Hu, Ming Guo

Journal of Electrochemistry

In controlling concentration of Ca²⁺ and PO₄^3- in electrodeposition solution, the HAP film on Ti alloy has been deposited directly. Using XRD and SEM we have learned that prepared HAP is intact in crystal and equal in dimension. Thermodynamic calculation indicated that the HAP is easer formation of than that TCP of. With the XRD, SEM analyses and thermodynamic calculation, the electrodeposition mechanism has been discussed. It was proved that electrodepositon is a two-stage process and formation of HAP is a direct process from solution ions to HAP crystal without precursor.

Study On Hydrogen Evolution Performance Of Nickel-Tin Electrode, Tian-Yi Chang, Bao-Hong Zhang, Wenbo Cong, Yao Luo

Journal of Electrochemistry

The cathode active material with low hydrogen evolution overvoltage was prepared by electroplating Ni-Sn alloy on the ferrous basic body.This kind of material can be applied in the diaphragm type of electrolytic tank to decrease cell voltage and save energy. On the condition according with cathode solution in the electrolytic tank (NaOH 120 g/L, NaCl 190 g/L, 90 ℃, i=150 mA/cm²), the overvoltage of hydrogen evolution was 88 mV. By the X-ray diffraction analysis, it was found that the structure of this kind of material was different from that of Ni-Sn alloy applied in traditional decoration. By using …

Some Consideration For Lithium-Ion Cells' Safety, Guang-Xia Hu, Jing-Ying Xie

Journal of Electrochemistry

The safety is the most important problem for lithium ion cells, especially for large lithium ion cells. In this paper, some information about lithium ion cells' safety can be learned by discussing several aspects of lithium ion cells, such as, materials of lithium ion cell, manufacturing processes, using conditions and so on.

Electrochemical Techniques For Measuring Anti-Corrosion Behavior Of The Thin Corrosion Inhibitor Layer To The 907a Steel, Yong-Tao Zhao, Jian-Hua Wu, Fan-Cai Chen, Zhong-Ping Gao, Jia Wang, Chang-Jiu Zhao

Journal of Electrochemistry

The corrosion inhibiting behavior of 907A steel, which was covered with thin inhibitor layers in moist seawater atmosphere,was studied. The electrochemical measurements, including EIS method and the coulostatic method, were used to atmospheric corrosioed monitor (ACM) under thin inhibitor layers to determine its corrosion rate. The results shown that the application of electrochemical methods such as the coulostatic technique and EIS could readily detect the on going process of film formation. Hence, the rapid evaluation of the thin inhibitor layers for 907A steel might be possible.

Synthesis And Characterization Of Lini0.8-XAlXCo0.2O2 As Cathodes For Lithium-Ion Batteries, Jun Zhang, Zhong-Kao Jin, Qing-He Yang, Qing-Mei Song, Xiao-Hua Ma, Xiang-Fu Zong

Journal of Electrochemistry

Single-phase solid solution of LiNi_0.8-xAl_xCo_0.2O₂ (0≤ x <0.1)had been synthesized and characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM). Their electrochemical performance was examined by charge-discharge cycling. The LiNi_0.71Al_0.09Co_0.2O₂ compound showed a discharge capacity of 152 mAh/g after 20 cycles that corresponds to 97.4% capacity retention. The beneficial effect of co-doping with Al and Co elements was corro-borated by slow scanning cyclic voltammograms(SSCV), electrochemical impedance spectrum (EIS) and differential scanning calorimetry (DSC) data on charged cathodes. These results show that the 2D-character of the crystal lattice was stabilized by co-doping with Al and Co, the phase transitions that occur during deintercalation or intercalation of Li-ions were significantly suppressed, …

Research Progress On Electrode Material In All-Vanadium Redox Battery, Hua Li, Shou-Wen Chang, Chuan-Wei Yan

Journal of Electrochemistry

An all-vanadium redox flow storage battery possesses many advantages over conventional storage batteries.The development statue of two types electrode materials (metal and compound type) is introduced in this article.

Initial Stages Of Copper Electrodeposition On Glassy Carbon Electrode, Ling Huang, Rui Zhang, Min Gu, Fang-Zu Yang, Shu-Kai Xu, Shao-Min Zhou

Journal of Electrochemistry

Initial stages of copper electrodeposition on glassy carbon electrode from acid sulphate solutions were studied using cyclic voltammetry and chronoamperometry. The electrolyte solution was a 0.05 mol.L^-1 copper sulphate, 1.4～1.8 mol⋅L^-1 sulphuric acid containing 1 mg·L^-1 2-mercaptobenzoimidazole, Results show that 2-mercaptobenzoimidazole produced an inhibition of the copper deposition, probably related to the adsorption,sulphuric acid promote copper electrodeposition. The initial deposition kinetics corresponded to a model including instantaneous nucleation and diffusion controlled growth.Addition of 2-mercaptobenzoimidazole and sulphuric acid did not change the initial nucleation of copper electrocrystallization, it increased the nucleation rate and the number density of nuclei …

Electrochemical Degradation Of Organic Wastewater By Three-Dimensional Electrode Reactor, Chun He, Tai-Cheng An, Ya Xiong, Dong Shu, Hui-Ling Hu, Xi-Hai Zhu

Journal of Electrochemistry

The electrochemical degradation of aniline was investigated using a novel electrochemical reactor, three-dimensional electrode reactor. The experimental results indicated that the reactor could efficiently remove aniline. The removal efficiency could be attributed to a combination of direct and indirect electrochemical reactions, that is, anodic oxidation and oxidation of electrogenerated H₂O₂ and hydroxyl radicals generated in electro-Fenton process. It was also observed that the removal efficiency was significantly dependent on applied voltage, Fe²⁺ concentration, pH value and electrolysis time. In the experimental range they all have a positive effect on the removal efficiency except for pH value. …

Dielectric Properties Of A Ferroelectric Copolymer Langmuir–Blodgett Film, Mahantappa S. Jogad, Stephen Ducharme

Stephen Ducharme Publications

We report measurements of the real (epsilon prime) and imaginary (epsilon double-prime) parts of the relative complex permittivity of a Langmuir–Blodgett film of ferroelectric copolymer of vinylidene fluoride (70%) with trifluoroethylene (30%). The measurements were made in the temperature range of 35 to 125° C, and frequency range of 19 Hz to 5 MHz. The results indicate low frequency loss due to conduction and dielectric loss peak near the ferroelectric–paraelectric phase transition.

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 5/16/02- 8/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible.

This process works well for the fabrication of metal fuel pins traditionally composed of alloys of uranium and plutonium, but does not work well when highly volatile actinides are included in the melt. The problem occurs both during the extended time period required to superheat the alloy melt as well as when the chamber must be evacuated. …

Corrosion Of Steel By Lead Bismuth Eutectic: Quarterly Report For May-June-July 2002, John Farley

Transmutation Sciences Materials (TRP)

The goal of this project is to understand the basic science of corrosion in the steel/LBE system.

We are taking more data, typically using the newly installed X-ray Photoelectron Spectrometry (XPS) apparatus, and analyzing our existing data. Undergraduate students Denise Parsons and Julia Manzerova have helped a great deal in the analysis of the data. We can obtain the elemental composition as a function of position within the sample. This gives clues to the migration of materials, the composition of the protective oxide layer, and the basic science of the corrosion process. We found dramatic differences between the exposed and …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Xiaolong Wu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fundamental issues related to the selection of a metallic fuel casting furnace design are presented and discussed including heating mechanisms, casting issues, crucible design, and issues related to the mass transport of americium. The process of evaluating all of these different criteria is undertaken to select a concept that would have the greatest chance of success for casting americium in a metallic fuel rod. Based on this evaluation process, a concept for the casting of metallic fuel pins containing high vapor pressure materials is selected and discussed. The important physics of this concept include mass transport of americium from the …

44th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 44th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Denver, Colorado, July 28 - August 1, 2002.

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems: Annual Progress Report (May 2001 – May 2002), Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate target materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including Alloy HT-9, Alloy EP 823 and Type 422 stainless steel. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these materials are being evaluated in environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. Further, the localized corrosion behavior of these alloys …

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823: Aaa Task-10 Quarterly (03/01, 2002 –05/31, 2002) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The objective of this task is to evaluate the elevated temperature tensile properties of Alloy EP-823, a leading target material for accelerator-driven waste transmutation applications. The test material will be thermally treated prior to evaluation of its tensile properties at temperatures relevant to the transmutation applications. The deformation characteristics of tensile specimens, upon completion of testing, will be evaluated by surface analytical techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The overall results are expected to provide a mechanistic understanding of high-temperature deformation behavior of Alloy EP-823 as a function of heat treatment.

Highlights of Accomplishment

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Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report 03/16/02- 06/15/02, 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. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high oxygen concentration, …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Phase Two, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Syntheses And Photoluminescence Of Zinc Oxide Polyaniline Coaxial Nanowires And Their Array, Zhi-Xin Zheng, Yan-Yan Xi, Ping Dong, Huai-Guo Huang, Jian-Zhang Zhou, Lin-Lin Wu, Zhong-Hua Lin

Journal of Electrochemistry

A novel nanomaterial, zinc oxide (ZnO) and polyaniline (PANI) coaxial nanowires and their array in the template, was synthesized using anodic aluminum oxide (AAO) membrane as template. The morphology of these coaxial nanowires was observed with transmission electron microscope (TEM). The experiments on photoluminescence (PL) of coaxial nanowires and their array in AAO membrane show that the visible emission band of ZnO shifts from 530 nm to 400 nm and the luminescence is enhanced for the coaxial nanowires array in AAO membrane,and the visible emission band shifts to a lower wavelergth (385 nm) for coatial nanowires in NaOH solution. Possible …

Electrochemical Properties Of Mixed Metal Oxide Coated Titanium Anodes In Seawater, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen

Journal of Electrochemistry

Mixed metal oxide coated titanium anodes prepared by thermal decomposition were characterized by scanning electron microscopy and electrochemical measurement, while the consumption rate of an anode was also measured in seawater. In order to examine the practical performances of mixed metal oxide-coated anodes, a simulating test on floating dock in seawater has also been carried out. The SEM results indicate that oxide layers exhibited a cracked-mud morphology which endows the anode with good electrocatalytic activity. The electrochemical measurements showed that mixed metal oxide-coated anodes exhibit excellent electrochemical activity and electrochemical stability in seawater. Owing to good corrosion resistance and low …

Corrosive Electrochemical Behavior Of Carbon Steel In Microbiological Medium, Jing Liu, Hong-Bo Fan, Hai-Ping Xu, Jia-Shen Zheng, Li-Ming Xu, Zong-Qiang Mao

Journal of Electrochemistry

Sulfate-reducing bacteria (SRB)grows and propagates, PH of the solution is dropped from 7.5 to 5.8, and forms the biofilms on carbon steel in culture medium. The micro-environment on the surface of carbon steel is changed under the biofilms, the factors accelerate the formation of the pitting corrosion. When the biofilm on carbon steel is cleaned out, the surface of carbon steel have the non-uniform pitting corrosion. The activity of SRB and the porous structure of biofilms induced the initiation and development of the pitting corrosion of carbon steel. The process of microbiologically induced corrosion (MIC) involves the development of SRB …

Recent Developments In The Electrolyte For Lic6/Electrolyte/Cathode Battery, Cui-Ying Wang, Sheng-Liang Zhao, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

We present a reviewed the development and status of electrolyte for LiC 6/electrolyte/cathode battery. The effect of the salt, solvent, additive and impurity on the conductivity of the electrolyte, formation of the solid-electrolyte-interphase (SEI) and cycle life of the battery were described.

A Blend Conducting Membranes For Direct Methanol Fuel Cells, Lei Li, Jun Zhang, Hong Wu, Yu-Xin Wang

Journal of Electrochemistry

An attempt was made to modify membranes for direct methanol fuel cells by blending Nafion or polystyrene sulfonic acid (PSSA) with polyvinylidene fluoride (PVDF) from their solutions. The proton conductivity and methanol barrier property as a function of the membrane compositions are discussed. Compared with the Nafion 117 membrane, the PVDF-Nafion blend membranes with 25 wt% of Nafion showed a decrease in the conductivity by about 2 orders of magnitude, and the methanol barrier properties increased about 3 orders of magnitude. If the ratio (σ/P) is adopted to characterize the performance of the membrane, the PVDF-PSSA and PVDF-Nafiion blend membranes …

Development Of 200～500 W Portable Proton Exchange Membrane Fuel Cell Power System, Li-Qing Hu, Li-Rong Zhou, Zheng Li, Jian-Wei Xia, Ming-Zhu Fu, Xin Wu, Yun Zhu

Journal of Electrochemistry

The Properties of the Portable PEM Fuel Cell Power Source are very unique compared with the common primary or rechargeable electro-chemical battery. This paper describes the In this work, of the 200～500 W portable PEM fuel cell power system, was developed. The system mainly composed of four subsystem: 1)Fuel cell stack; 2)Air delivery; 3)Hydrogen source; 4)Heat dissipation and system control.