• Title/Summary/Keyword: ion chemistry

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CASPT2 Study on the Low-lying Electronic States of 1,3,5-C6H3Cl3+ Ion

  • Yu, Shu-Yuan;Zhang, Cheng-Gen;Wang, Shu-Jun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1511-1515
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    • 2014
  • The multiconfiguration second-order perturbation theory (CASPT2) and complete active space self-consistent field (CASSCF) methods were employed to calculate the geometries and energy levels for the low-lying electronic states of 1,3,5-$C_6H_3Cl{_3}^+$ ion. The CASPT2 values for the 1,3,5-$C_6H_3Cl{_3}^+$ ion were in reasonable agreement with the available experimental values. The current calculations augmented previous theoretical investigations on the ground state and assigned the low-lying excited electronic states of the 1,3,5-$C_6H_3Cl{_3}^+$ ion. The Jahn-Teller distortion in the excited electronic state for the 1,3,5-$C_6H_3Cl{_3}^+$ ion were reported for the first time.

Mercury Ion Monitoring in Mercury Plating Bath by Anodic Stripping Voltammetry

  • Park, Mijung;Yoon, Sumi;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.7 no.3
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    • pp.241-244
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    • 2016
  • Anodic stripping voltammetry (ASV) is successfully applied in mM level detection of mercury ion in an electroplating bath which is currently used in preparing a cathodic electrolyzer. Glassy carbon electrode is used for the detection and the optimum condition obtained is 10 s deposition at −1.4 V vs. Ag/AgCl and stripping by scanning from −1.4 to +0.4 V vs Ag/AgCl at 50 mV/s. By applying the method, the mercury ion concentration in the electroplating bath could be successfully monitored during the plating.

Low Energy Ion-Surface Reactor

  • Choi, Won-Yong;Kang, Tae-Hee;Kang, Heon
    • Bulletin of the Korean Chemical Society
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    • v.11 no.4
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    • pp.290-296
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    • 1990
  • Ion-surface collision studies at low kinetic energies (1-100 eV) provide a unique opportunity for investigating reactions and collision dynamics at surfaces. A special ion optics system for generating an energy- and mass-selected ion beam of this energy is designed and constructed. An ultrahigh vacuum (UHV) reaction chamber, in which the ions generated from the beamline collide with a solid surface, is equipped with Auger electron spectroscopy (AES) and thermal desorption spectrometry (TDS) as in-situ surface analytical tools. The resulting beam from the system has the following characteristics : ion current of 5-50 nA, energy spread < 2eV, current stability within ${\pm}5%,$ and unit mass resolution below 20 amu. The performance of the instrument is illustrated with data representing the implantation behavior of $Ar^+$ into a graphite (0001) surface.

Study of Lithium Ion Capacitors Using Carbonaceous Electrode Utilized for Anode in Lithium Ion Batteries (이차전지 음극용 탄소 전극을 이용한 리튬이온 커패시터 연구)

  • Oh, Rye-Gyeong;Hong, Jung-Eui;Yang, Won-Geun;Ryu, Kwang-Sun
    • Applied Chemistry for Engineering
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    • v.24 no.5
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    • pp.489-493
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    • 2013
  • The most common carbonaceous anode materials of lithium ion batteries (natural graphite, artificial graphite, hard carbon, and mesocarbon microbeads) were utilized as an electrode in lithium ion capacitors. It could be able to enhance the energy density of capacitors due to the intercalation of lithium ion. In this work, the properties of capacitors using the symmetric electrode were measured by organizing coin cell typed capacitors. Also, we made other capacitors having pre-intercalated lithium ions at one side of the electrode. The results of electrochemical measurements for these capacitors show that the storage capacitance was appeared. In other words, if the migration of lithium ions is supplied continuously in the electrolytes, lithium ions can be diffused into the carbonaceous materials. And it results in the improvement of capacitance compared to only using symmetric carbonaceous electrodes. Also, we conducted the same measurement with graphene oxide having a the large specific area in the same condition. Herein, we recognized that the large specific area is extremely important for supercapacitors.

Separation of Alkali and Alkaline Earth Metal Ions Using Novel DBPDA Ion Exchanger and Its Ion Exchange Properties (새로운 DBPDA 이온교환체를 사용한 알칼리 및 알칼리 토금속 이온들의 분리와 그의 이온교환 성질)

  • Kim, Dong Won;Kim, Chang Suk;Choi, Ki Young;Jeon, Young Shin
    • Analytical Science and Technology
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    • v.6 no.3
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    • pp.261-265
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    • 1993
  • The ion exchange capacity of DBPDA ion exchanger, {(4,5):(13,14)-dibenzo-6, 9, 12-trioxa-3, 15, 21-triazabicyclo [15.3.1] heneicosa-1(21), 17, 19-triene-2, 16-dione : DBPDA ion exchanger} was 4.2meq/g. The distribution coefficients of alkali and alkaline earth metal ions in the various concentrations of hydrochloric acid were determined using DBPDA ion exchanger. Also alkali and alkaline earth metal ions were separated using DBPDA ion exchanger. From these results the effect of pH of solution and ionic radii of the metal ions on the distribution coefficients of alkali and alkaline earth metal ions were discussed.

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Speciation of Cd, Cu and Zn in Sewage Sludge-Treated Soils Incubated under Aerobic and Anaerobic Conditions

  • Lee, Sang-Mo;Cho, Chae-Moo;Yoo, Sun-Ho
    • Journal of Applied Biological Chemistry
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    • v.42 no.2
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    • pp.85-91
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    • 1999
  • The incubation study was conducted under aerobic and anaerobic conditions to study the release of the kinetically labile forms (i. e. chelating ion or anion forms) of Cd, Cu and Zn in sludge-untreated soil ("Control"), sludge 50 and $100dry\;Mg\;ha^{-1}$ treated soils ("Soil-Sludge mixtures"), and sewage sludge ("Sludge"). The chelating ion and anion exchange membranes were embedded into the samples and incubated for 16 weeks under aerobic and anaerobic condition. The total amounts of chelating ion or anionic forms of Cd were too little to be measured during both aerobic and anaerobic incubation. On the other hand, the total amounts of chelating ion or anionic forms of Cu and Zn slightly increased throughout the incubation period under both incubation conditions. For "Control" and "Soil-Sludge mixtures" treatments, the total amounts of Cu and Zn in chelating ion and anion exchange membrane were little difference between aerobic and anaerobic condition, and the total amounts of chelating ion form of Cu and Zn were not different from the those of anionic form of Cu and Zn. However, for "Sludge" treatment, the total amounts of Cu and Zn in anion and chelating ion exchange membrane were greater under aerobic condition than under anaerobic condition, and the total amounts of chelating ion form of Cu and Zn were greater than those of anion form of Cu and Zn under both incubation conditions.

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Preparation of NH4+-β"-alumina as a Protonic Solid Electrolyte by Ion Exchange Reaction (이온교환반응에 의한 양성자 고체 전해질 NH4+-β"-alumina의 제조)

  • Lee, Jun-Hee;Han, Choon-Soo;Lee, Sung-Tae;Lee, Ki-Moon;Lee, Dae-Han;Lim, Sung-Ki
    • Applied Chemistry for Engineering
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    • v.22 no.3
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    • pp.255-260
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    • 2011
  • $NH_4{^+}-{\beta}^{{\prime}{\prime}}$-alumina which is expected to an inorganic solid electrolyte of high temperature polymer electrolyte membrane fuel cells (PEMFC) was prepared by ion-exchange reaction of $K^{+}-{\beta}^{{\prime}{\prime}}$-alumina pellet with $NH_4NO_3$ aqueous solution and molten $NH_4NO_3$ salts as an ion-exchange medium in the autoclave and the heating mentle reaction. In the autoclave reaction, the concentrations of $NH_4NO_3$ solution was chosen at 5 and 10 M. Each ion-exchange reaction was carried out at 130, 150, 170, and $200^{\circ}C$ for 2, 4, 6 and 8 h. In the heating mentle reaction, ion-exchange was performed at $200^{\circ}C$ for 2, 4, 6 and 8 h with molten $NH_4NO_3$ salts. In order to determine the effect of reaction times, each ion-exchange reaction was repeated 3 times. The phase stability and the ion-exchange rate of $NH_4{^+}-{\beta}^{{\prime}{\prime}}$-alumina were analyzed by XRD and ICP.