Chemistry Commons^™

Evaluation Of Fluorapatite As A Waste-Form Material: First Quarter Report (2004-05), October 1 - December 31, 2004, Dennis W. Lindle, Oliver Hemmers

Separations Campaign (TRP)

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF₄, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form …

The Electrochemical Separation Of Curium And Americium: Quaterly Report August-December 2004, 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. The following pages outline the progress on our project to date. We have been actively performing research on this project for three months and are currently on schedule in terms of the proposed timelines.

The initial focus of the project involved setting up the laboratories for the studies outlined in the grant proposal. The instrumentation needed included an electrochemical work station that will perform the bulk of the electrochemical studies. This instrument will complement the electrochemical instrumentation in Dr. Hatchett’s laboratory and …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, October 2004 To December 2004, Earl Wolfram, Thomas Hartmann, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert matrix fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of ²³⁹Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide …

The Characterization Of Nanosized Nickel-Zinc Ferrites Synthesized Within Reverse Micelles Of Ctab/1-Hexanol/Water Microemulsion, Vuk Uskoković, Miha Drofenik, Irena Ban

Pharmacy Faculty Articles and Research

Stoichiometric nanocrystalline nickel–zinc ferrites were synthesized by a reverse micelle method following a multi-microemulsion approach. Different pH values were chosen for the alkali precipitating reaction during the synthesis of different powders. Synthesized, as-dried and subsequently calcined powders were characterized in terms of their magnetic properties. XRD analyses and specific-surface area measurements were used to determine the average particle sizes of the synthesized samples. DCS and TGA measurements were performed to reveal the phase transitions within the samples at elevated temperatures, whereas TEM was used to view and record the microstructure of the nanosized ferrite samples. A possible mechanism of the …

Electrochemical Behaviours Of Hemoglobin-Ddab-Modified Powder Microelectrode And The Application Of The Powder Microelectrode In Determination Of Nitric Oxide, Zhi-Mou Guo, Huan Liu, Jian Chen, Wen-Ting Zhang

Journal of Electrochemistry

The electrochemical behaviours of DDAB-Hb-PME were studied in this paper. The (apparent) surface concentration of Hb was enhanced greatly by using the powder microelectrode (technique). NO reacts with Hb and absorbs on the surface of the modified carbon powder. Therefore, the output of the electrode was enhanced greatly by employing PME with higher reaction surface (area). The sensitivity of DDAB-Hb-PME is 3.1 mA/μmol·L~(-1)·cm~(2), which is much larger than the values obtained with the traditional electrodes. The detection limit is 9 nmol·L~(-1) and the linear response range is 9～100 nmol·L~(-1).

Electrochemical Behavior Of Aluminized Steel In Seawater Environment, Cheng-Hao Liang

Journal of Electrochemistry

The electrochemical behavior of aluminized steel in seawater has been studied by immersion test and electrochemical technology. The results indicate that compared with 20# steel, the aluminized steel has lower corrosion potential and stronger anodic activity in seawater. Its anodic solution will occur at low potential. The immersion test shows that the corrosion rates of aluminized steel and 20# steel are 5.80 mg/dm~2 dand 3.36 mg/dm~2 d, respectively. Through the X-ray diffraction patternanalysis, it was found that chloride ions exit in the corrosion products of aluminized steel. It proves the participation of chloride ions in the process of corrosion, which …

Preparation And Photo-Catalyst Properties Of The Α-Fe_2o_3-Tio_2 Films On Sodium Alginate Polymer, Li-Qin Chen, Huai-Zhen Zhong, Ri-Yao Chen, Xi Zheng, Zhen Chen

Journal of Electrochemistry

Three new nano thin films of α-Fe_2O_(3)、TiO_2 and α-Fe_2O_(3)-TiO_2 by doping their powder with sodium alginate polymer were prepared. Surface structure and catalytic activities of the films were characterized by FTIR、XRD、PL、TEM and I-V techniques. The results of UV-visible absorption showed that the methylene blue was mineralized in aqueous of α-Fe_2O_(3)/SA、TiO_2/SA and (α-(Fe_2O_(3)))-TiO_2 /SA upon radiation with ultra violet light. α-Fe_2O_(3) enhanced their photo-decolorized-activities by doping 15% TiO_2.

Investigation Of Pulse Potential-Modulated Coulometry For Co_2 Detection, Hai-Chuan Wang, Bing-Liang Wu

Journal of Electrochemistry

A pulse potential-modulated technique was applied to measure the concentration of CO_2 in gas samples. In the first step, an anodic pulse and a consequent cathodic pulse were used to remove the organic pollutant and surface oxide on the surface of the platinized Pt gauze electrode before each experiment. As following, a given potential step was used to reduce the CO_2 into adsorbed intermediate on Pt surface, and the adsorbates produced were oxidized by a following anodic potential step. At same time the oxidation current of adsorbates were measured. A certain relation exists between the concentration of CO_2 and the …

Electrocatalytic Performances Of Carbon Nanotube Air Electrode For Oxygen Reduction, Feng-Ming Zhao, Chun-An Ma

Journal of Electrochemistry

The air electrodes with different mass ratio of Pt/active carbon or carbon nanotube as catalyst layer material have been prepared. The electrocatalytic performances for oxygen reduction were evaluated by means of polarization curve and electrochemical impedance spectroscopy (EIS). The results disclosed that carbon nanotubes dealt with nitric acid in the catalyst layer had been improved obviously on the electrocatalytic activity. After the surface of carbon nanotube was oxygenated and aggraded with platinum, the catalyst had obviously effects on the electrocatalytic activity. The air electrode with the mass ratio of active carbon to Pt/carbon nanotube in 4∶1 showed better electrocatalytic activity, …

The Investigation Of Bafesi/C Alloy Composite As Anode Materials For Li-Ion Battery, Rui-Xiang Feng, Hua Dong, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

A novel BaFeSi/C composite was prepared by mechanical ball milling, and lithium insertion reactions on the composite electrode were investigated by cyclic voltammetry ,charge-discharge measurements, XRD and XPS spectroscopy. It is demonstrated that the capacity retention with indiscernible capacity decas during charge-discharge cycling. The improved cycling ability of the composite is suggested from a cooperative action by inactive FeSi_(2 )and BaSi_2 matrix and outer graphite shell, which both buffer the volumetric changes of the active Si phase and provide a good connection for electronic and ionic conduction during lithium insertion and extraction processes.

Studies On The Electrochemical Preparation And Electrochemical Properties Of Conducting Polymers——Brief Introduction To The Research Work Of Electrochemistry Of Conducting Polymers In Cas Key Laboratory Of Organic Solids(I), Yong-Fange Academy Of Sciences Li

Journal of Electrochemistry

Conducting polymers have drawn much attention since the discovery of conducting polyacetylene in 1977, due to the novelty and curiosity of their structure and properties as well as their promising applications in many aspects. Among the studies of conducting polymers, the electrochemical preparation and electrochemical properties of conducting polymers are of special importance, because the electropolymerization is a main method for preparing conducting polymer films and the electrochemical properties are the basis for their applications in the fields of electrode materials for batteries, electrocatalysis, electrochromic display, etc. We are one of the earliest research groups in the world to perform …

Study On Mass Transport In Liquid Layer Adjacent To The Electrode Through Transmission Vop-Spectroellipsometry, Wei Zhu, Yangyu-Ru Yangyu-Ru, Zong-Qing Huang

Journal of Electrochemistry

In electrochemical system, the mass transport process in liquid layer adjacent to electrode is studied through theoretical analysis only.The diffusion process can be analyzed theoretically by Fick's law for homogeneous media. Up to now, none of satisfied experimental method has been reported for studying mass transport of a whole process in liquid media yet. This paper described the experimental approach to explore mass transport in electrochemical system by transmission Vop-spectroellipsometry briefly.

Improvement And Its Mechanism Of Storage Performance Of Ni-Mh Battery, Xiao-Feng Li

Journal of Electrochemistry

The storage performance of nickel-metal-hydride (Ni-MH) battery was studied by using galvanostatic charge-discharge and cyclic voltammetry. The experimental results indicated that CoOOH could not be completely restored after its being thoroughly reduced at lower potential, which might weaken electric conduction network in the positive electrode and result in fading of electrochemical properties of Ni-MH battery. Addition of nickel powder as a conductive agent into the positive electrode was beneficial to the capacity recovery after storage.

Anodic Dissolution Of Aluminum In Koh-Ethanol Solutions, Hai-Bo Shao, Jian-Ming Wang, Xiao-Yan Wang, Yi Zheng, Jian-Qing Zhang

Journal of Electrochemistry

The feasibility of employing aluminum in KOH ethanol solution as a battery anode system was discussed. Weight loss measurement showed that the corrosion rate of Al is low enough to be used in sealed batteries. Through the measurements done by anodic polarization, EIS and galvanostatic discharge, it was found that A1 is electrochemical active in a wide potential range in this system, and its discharge mechanism is similar to that of A1 in aqueous solution. The discharge potential increased rapidly after a period of time, which might be caused by the discharge products depositing on the electrode surface.

The Inhibition Synergistic Effect Between Imidazoline Derivative And Thiourea, Jing-Mao Zhao, He-Xia Liu, Wei Di, Yu Zuo

Journal of Electrochemistry

The inhibition synergistic effect between imidazoline and thiourea for carbon steel in CO_2 saturated brine solution was investigated by using weight-loss method, polarization curves measureament and XPS. The results showd that the inhibition efficiency increased significantly when imidazoline derivative was added as a corrosion inhibitor in the solution together with thiourea. The N and S atoms in the inhibitor film adsorbed on the surface of carbon steel, and N atoms predominated in the film near the solution and decreased gradually with the film depth and finally S atoms were the major element in the film near the matrix. It was …

The Electrochemical Performance Of Modified Spinel At Elevated Temperature, Zhen-Ping Cai, Xiao-Hong Chen, Shi-Gang Lu, Ming-Xun Li, Wei-Hua Jin

Journal of Electrochemistry

The modified LiMn_2O_4 cathode materials for lithium ion batteries have been synthesized by solid-state reaction. The crystal structure and electrochemical performance of products have been investigated by SEM、XRD and electrochemical measurements. The XRD analysis indicated that all the synthesized products possess Fd3m spinel LiMn_2O_4 structure. Those modified LiMn_2O_4 materials showed improved cycling capacity over pure spinels at high temperature and room temperature.

Preparation And Electrochemical Magnesium Insertion Behaviors Of Mgv_2o_6, Hua-Tang Yuan, Li-Fang Jiao, Jian-Sheng Cao, Xiu-Sheng Liu, Ming Zhao, Yong-Mei Wang

Journal of Electrochemistry

MgV_2O_6was synthesized by conventional solid-state reaction from MgO and V_2O_(5)as starting materials. X-Ray diffraction analysis showed that the prepared sample belongs to the monoclinic structure. Electrochemical magnesium insertion from aprotic electrolytes such as organomagnesium halides into this host was found possible and exhibited charge/discharge circulation.

Electrochemical Investigations On Pitting Susceptibility Of Iron-Based Alloy, Wei-Shan Li, Hong-Yu Chen, Zhong-Zhi Yuan, Hong Li, Qi-Ming Huang, Dong-Sheng Lv

Journal of Electrochemistry

The formation process of passive film on iron and electronic properties and pitting susceptibility of an iron-based alloy are investigated by using linear potential sweep, alternative current impedance and electrochemical nose technologies. The relationship between reciprocal square capacitance and potential following the Mott-Schottky behavior is limited at a narrow rang of low potentials. At higher potentials, linear relationship between reciprocal capacitance and potential is obtained, which is ascribed to the increasing thickness of the passive film with potential. The donor density of the passive film is influenced by the formation potential of the film, passivator and microstructure. The decrease in …

Lico_(X)Ni_(1-X)O_2 Cathode Materials Prepared By Electrolysis Of Co And Ni, Jin-Ping Wei, Xin Sun, Xiao-Yu Wang, Xi-Kui Bian, Jin-Ling Zhai, Yan-Jie Yan-Jie

Journal of Electrochemistry

A new electrolytic method was developed to prepare LiCo_(x)Ni_(1-x)O_2 as a cathode material of lithium-ion battery. Contrary to the traditional method, electrolytic method is a potential method with simple process to industrialization and no pollution. Metal cobalt and nickel were electrolysed in parallel to prepare the precursor of Co_( x )Ni_(1- x )(OH)_2.Different compositional precursors could be conveniently prepared by changing electrolytic current. The LiCo_(0.3)Ni_(0.7)O_2 cathode prepared by this method was found favorable charge-discharge and cycle properties. For the LiCo_(0.3)Ni_(0.7)O_(2 )cathode material, the discharge capacities in the 1st and 50th cycles were 163 mAh/g and 140 mAh/g with charge retention …

Applications Of New Activated Carbon Meterials In The Electric Double-Layer Capacitor, Jian-Jun Zhang

Journal of Electrochemistry

A new type activated carbon whose precursor was coconut shell could be obtained using specific physics-chemistry activation, and the activated carbon was applied as the material of electrode in EDLC(electrical double-layer capacitor),which had a large specific capacitance,and could charge and discharged in some large currents. Carbon dioxide and acid were used to modify carbon,and the effects of post-treatment on surface area and pore volume were investigated. A moulding method which has influence on some properties of carbon electrode with PTFE additive was researched in the paper.

Effect Of Fe~(3+) Dopen Of Titanium Dioxide Film On Absorption Spectra And Photo Catalysis, Mei-Qun Xiao, Jia-Nian Shen, Moucheng Li, Peng-Fei Wu, Dong Liu, Yu-Juan Zhang

Journal of Electrochemistry

Photo-catalytic titanium dioxide film in nano crystalline has been prepared by electrochemical oxidation process and adding different amount of ferric ion into the electrolyte during the anodic oxidation.The effects of Fe~(3+) dopen on absorption spectra and photo-catalytic of the titanium dioxide films have been studied. It shows that the Fe~(3+) dopen caused the red shife of the absorption edge for the incoming light and exhibited the improved photocatalytic reactivity.

Electrical Properties And Raman Scattering Study Of Single Crystal Cs2nb4o11, Jianjun Liu, E. P. Kharitonova, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy

Chemistry Faculty Publications

We studied temperature dependence of complex capacitance, impedance, and polarized Raman spectra of single crystal Cs2Nb4O11. First, we observed a sharp-shaped peak at 165 ^oC in the complex capacitance, then found drastic changes in the Raman spectra in the same temperature range. Utilizing the pseudosymmetry search of structure space group, we attributed the observed anomalies to a structural change from the room temperature orthorhombic Pnn2 to another or- thorhombic Imm2. We also measured room temperature polarized Raman spectra in different symmetries of normal vibrations and assigned high wavenumber Raman bands to the internal vibrations of NbO6 octahedra and NbO4 …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix, Spencer M. Steinberg, Gary Cerefice, David W. Emerson

Separations Campaign (TRP)

The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of radioactive iodine. During the first two years of this program we have examined the potential of Fullerene Containing Carbon compounds (FCC) developed by KRI, and natural organic matter (NOM) as sorbents for iodine released during the reprocessing of nuclear fuel. This work involved the development of bench-scale testing of the FCC and NOM material in a simulated process off-gas environment.

Research Objectives and Goals

• Develop bench-scale experimental set-up and procedures for simulating PUREX head-end vapor phase; Develop experimental procedures …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quarterly Report August-September 2004, Spencer M. Steinberg

Separations Campaign (TRP)

During first year of the project we were able to demonstrate iodine sorption by a sphagnum peat and Ca(OH)2 mixture. We decided to explore varying the ratio of Ca(OH)2 to sphagnum on the retention of iodine in both the iodine generator experiments and the fuel rod simulator experiments.

We also constructed a device for simulating the dissolution of fuel rods. Early experiments were impacted by sorption of iodine onto various components of the sorption train. We have eliminated or minimized iodine sorption by the system components. We retested both FCC and the sphagnum using this device. In these experiments a …

Evaluation Of Fluorapatite As A Waste-Form Material: Fourth Quarter Report, June 1 - September 30, 2004, Dennis W. Lindle, Oliver Hemmers

Separations Campaign (TRP)

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF₄, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, July 2004 To September 2004, Kenneth Czerwinski, Earl Wolfram

Fuels Campaign (TRP)

This project will examine inert fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10 % of ²³⁹Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide …

Nondipole Effects In The Photoionization Of Xe 4d5/2 And 4d3/2: Evidence For Quadrupole Satellites, Oliver Hemmers, Renaud Guillemin, D. Rolles, A. Wolska, Dennis W. Lindle, K. T. Cheng, W. R. Johnson, H. L. Zhou, S. T. Manson

Environmental Studies Faculty Publications

Measurements of nondipole parameters in spin-orbit-resolved Xe 4d photoionization demonstrate dynamical differences arising from relativistic effects. The experimental data do not agree with relativistic random-phase approximation calculations of single ionization dipole and quadrupole channels. It is suggested that the discrepancy is due to the omission of multiple-excitation quadrupole channels, i.e., quadrupole satellite transitions.

Probing Cation Antisite Disorder In Gd2ti2o7 Pyrochlore By Site-Specific Nexafs And Xps, Ponnusamy Nachimuthu, S. Thevuthasan, Mark H. Engelhard, W. J. Weber, D. K. Shuh, N. M. Hamdan, B. S. Mun, E. M. Adams, D. E. Mccready, V. Shutthanandan, Dennis W. Lindle, G. Balakrishnan, R. C. Ewing

Chemistry and Biochemistry Faculty Research

Disorder in Gd₂Ti₂O₇ is investigated by near-edge x-ray-absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy (XPS). NEXAFS shows Ti⁴⁺ ions occupy octahedral sites with a tetragonal distortion induced by vacant oxygen sites. O 1s XPS spectra obtained with a charge neutralization system from Gd₂Ti₂O₇(100) and the Gd₂Ti₂O₇ pyrochlore used by Chen et al. [Phys. Rev. Lett. 88, 105901 (2002)], both yielded a single peak, unlike the previous result on the latter that found two peaks. The current results give no evidence for …

Synergisms Of Electric Or Electromagnetic Fields And Photodynamic Effects Induce Apoptosis And Necrosis Of Cancer Cells, Radeva Maria, Lambrera Maya, Angelova Plamena, Traitcheva Nelly, Berg Hermann

Journal of Electrochemistry

Weak pulsating sinusoidal electromagnetic fields (PEMF) have been applied to change membrane permeation and induction of apoptosis (necrosis). In the case of suspension of human cancer cells U-937 and K-562 inside of Helmholtz-coils the amplitude of PEMF B=10 and at 39mT (at 50 Hz) was combined gradually with the cytotoxic agent actinomycin-C on one hand with its novel photodynamic activity on the other. Depending on temperature, pH-value and treatment time the necrosis of these cells was determined by means of trypan blue staining as well as the induced apoptosis by FACScan technique. Synergisms were discovered yielding high rates of cell …

Studies On The Electrochemical Behavior Of Copper Paratolysulfate And Its Complexes, Ji-Guo Song, Pei-Kang Shen

Journal of Electrochemistry

Copper (II) paratolysulfate has been synthesized and characterized by thermo-gravimetric (TG) measurements and differential scanning calorimetric (DSC) analysis. This salt can easily lose all crystal water and the dehydrated salt does not deliquesce in the air. It is found for the first time that the complex of Cu(p-OTs)_(2)/ethanolamine(1∶1) can catalyze the oxidation of 1,1′-bi-2-naphthol in DMSO and DMF, while the process is difficult to perform in H_(2)O and CH_(3)OH. The electrochemical behaviors of both Cu(p-OTs)_(2) and its complexes with ethanolamine have been studied on platinum electrode in DMSO, DMF, (CH_(3)OH) and H_(2)O respectively. The complexes of various copper salts with …