• Title/Summary/Keyword: electrolyte solutions

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Effects of Electrolyte Concentration on Growth of Dendritic Zinc in Aqueous Solutions (수용액중 아연 덴드라이트의 성장 반응에 미치는 전해질 농도의 영향)

  • Shin, Kyung-Hee;Jung, Kyu-Nam;Yoon, Su-Keun;Yeon, Sun-Hwa;Shim, Joon-Mok;Joen, Jae-Deok;Jin, Chang-Soo;Kim, Yang-Soo;Park, Kyoung-Soo;Jeong, Soon-Ki
    • Journal of Hydrogen and New Energy
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    • v.23 no.4
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    • pp.390-396
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    • 2012
  • In order to understand the nature of dendritic zinc growth, electrochemical zinc redox reaction on nickel plate was investigated in aqueous solutions containing different concentrations, 0.2, 0.1 and 0.02 $mol{\cdot}dm^{-3}$ (M), of zinc sulfate ($ZnSO_4$) or zinc chloride ($ZnCl_2$). Zinc ion was efficiently reduced and oxidized on nickel in the high-concentration (0.2 M) solution, whereas relatively poor efficiency was obtained from the other low-concentration solutions (0,1 and 0.02 M). Cyclic voltammetry (CV) analysis revealed that the 0.2 M electrolyte solution decomposes at more positive potentials than the 0.1 and the 0.02 M solutions. These results suggested that the concentration of electrolyte solution and anion would be an important factor that suppresses the reaction of the zinc dendrite formation. Scanning Electron Microscopy (SEM) data revealed that the shape of dendritic zinc and its growing behavior were also influenced by electrolyte concentration.

The Effect of Electrolyte on the Viscoelastic Characteristics of PPy Thin Film Using QCA (QCA를 이용한 폴리피롤 박막의 점탄성 특성에 대한 전해질 영향)

  • Song, Seong-Hun;Kim, Jong-Min;Han, Dae-Sang;Park, Jin-Young;Park, Ji-Sun;Chang, Sang-Mok
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.784-788
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    • 1999
  • In this work, we analyzed the viscoelastic characteristics of electrochemically polymerized polypyrrole(PPy) thin film in various electrolyte solutions, $Na_2SO_4,\;Na_2CO_3$ and SDS + $NaClO_4$, using QCA. The characteristics of redox reaction of electrochemically polymerized PPy thin film for 180 sec in each electrolyte, was investigated in 0.1 M $NaClO_4$ electrolyte solution by cyclic voltammetry method. We used one side of quartz crystal electrode as a working electrode and measured the resonant frequency, resonant resistance and current as analytical parameters. As the results, we suggest that electrochemically polymerized PPy thin film in various electrolyte solutions shows tendency changing from elastic characteristics to viscoelastic one in the order of $ClO_4{^{-}}\;+\;DS^-,\;SO_4{^{-2}}$ and $CO_3{^{-2}}$.

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The Effects of Ambient Ions on the Growth of Gold Nanoparticles by Laser Ablation in Liquid

  • Kwon, Hyejin;Kim, Kuk Ki;Song, Jae Kyu;Park, Seung Min
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.865-870
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    • 2014
  • Gold nanoparticles (AuNPs) were synthesized by laser (Nd:YAG, ${\lambda}$ = 1064 nm) ablation of a gold target immersed in various aqueous electrolyte solutions (7 mM of LiCl, NaCl, KCl, NaBr, and NaI) as well as in deionized water. The surface plasmon absorption and EDX of AuNPs so produced as well as their TEM images were analyzed to investigate the effects of ambient ions on the growth and aggregation of NPs. The size of AuNPs was reduced by laser ablation in the presence of chloride and bromide ions while it increased drastically when AuNPs were formed in iodide solution. Interestingly, triangular nanoplates were synthesized only in iodide solution. Surface chemistry on AuNPs in various electrolyte solutions was explored to elucidate the role of ions on the size and stability of AuNPs.

Voltammetric Assay of Silver Ions in Frog's Tissue

  • Ly, Suw-Young;Lee, Jin-Hui;Lee, Chang-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.139-145
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    • 2013
  • The electrochemical analysis of silver ion was performed using cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry, and electrode cell systems were fabricated with graphite pencil electrode (GE) of working, reference and counter electrodes. Also electrolyte was the use of sea water as electrolyte solutions instead of ionic controlled solutions. The optimum analytical conditions for the cyclic and stripping parameters were determined using GE. The results approached the microgram working ranges of SW(ug/L) and CV(ug/L) Ag, and the optimum conditions were applied to frog's tissue and the food samples.

Theoretical Calculation of Hydration Number and Activity Coefficients of Salts in Concentrated Electrolyte Solutions (진한 전해질 용액 중에서 염의 수화수와 활성도 계수에 관한 이론적 연구)

  • Yong Kil Sung;Mu Shik Jhon
    • Journal of the Korean Chemical Society
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    • v.14 no.2
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    • pp.185-192
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    • 1970
  • The extension of the theory of the electrolyte solution to the calculation of the hydration number and the mean activity coefficient of some 1:1 electrolytes in the concentrated solutions has been made. In this derivation, the hydration number has been calculated from the equation of the dielectric constant proposed by Hobbs, Jhon, and Eyring, and the mean activity coefficient from the theoretical formula developed by Jhon and Eyring. The agreement between theory and experiment over a.wide concentration range is quite satisfactory.

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Electrolyte-concentrations Effects on SEI Formation on Graphite Negative Electrode in EC-based Electrolyte Solutions (흑연전극상의 SEI 형성에 미치는 EC계 전해질 농도의 영향)

  • Choi, Dong-Gui;Jeong, Soon-Ki
    • Proceedings of the KAIS Fall Conference
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    • 2007.11a
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    • pp.356-358
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    • 2007
  • 본 논문에서는 농도가 다른 EC계의 전해질 용액 중에서 흑연의 Cyclic voltammetry(CV)를 측정하였다. CV후 전극표면에 생성된 SEI를 투과형 전자현미경으로 분석한 결과, PC계에서 얻어지는 결과와 유사하게 충 방전 반응 및 생성된 SEI의 성질이 전해질의 농도에 크게 의존하고 있음을 확인하였다.

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Analysis of Tertiary Amines and Quaternary Ammonium Salts in Electrolyte Solutions of Electrolytic Capacitors by Ion-Pair Liquid Chromatography (전해커패시터 전해액 중 3차 아민과 4차 암모늄염의 이온쌍 액체크로마토그래피에 의한 분석)

  • Chung, Yongsoon;Chang, Cheolkyu;Lee, Jeongmi;Lee, Younghoon;Kim, Seong Ho
    • Analytical Science and Technology
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    • v.10 no.4
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    • pp.231-239
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    • 1997
  • We developed a procedure that can effectively separate and determine tertiary amines and quaternary ammonium salts in some samples with reverse phase ion-pair high performance chromatography, employing indirect spectrophotometric detection method. Detection and ion-pairing reagents used in this study were benzyl trimethylammonium chloride (BTMACl) and sodium dodecyl sulfate(DDSANa), respectively. Eluting the electrolyte solutions of some commercial electrolytic capacitors with a MeOH(40):water(60) eluent (pH 8.5 adjusted with NH4Cl-NH3 buffer) containing 0.010M DDSANa and 0.004 M BTMACl through Supelco LC-18 or ${\mu}$-Bondapak phenyl column, amines and ammonium salts contained in the sample were successfully separated and determined. Varying the composition, especially the content of quaternary ammonium salts, of electrolyte solutions based on this analysis. we could prepare the low impedance(0.08~0.13) electrolytic capacitors with excellent electrical properties and it was a confirmation that the analysis is favorable.

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Modeling and Measurements of the Activity Coefficients and Solubilities of Amino Acids in the L-valine/electrolyte and L-proline/electrolyte Aqueous Solutions (L-Valine/전해질 및 L-Proline/전해질 수용액에서 아미노산의 활동도계수와 용해도의 측정 및 모델링)

  • Lee, Bong-Seop;Kim, Ki-Chang
    • Korean Chemical Engineering Research
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    • v.50 no.1
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    • pp.93-105
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    • 2012
  • Activity coefficients and solubilities of L-Valine and L-Proline in aqueous solutions containing each of four electrolytes such as NaCl, KCl, $NaNO_3$ and $KNO_3$ were measured at 298.15 K. The measurements of activity coefficients were carried out in the electrochemical cell coupled with two ion-selective electrodes (cation and anion), and the solubilities were measured by the gravimetric analysis of saturated solutions in equilibrium with the solid phase of amino acid. The measured activity coefficients of electrolytes and amino acids were correlated with the theoretical thermodynamic model presented in the previous work [Korean Chem. Eng. Res. 48(4), 519(2010)]. It was found that the activity coefficients of amino acids and electrolytes described based on the our previous model were well agreeable with experimental data. Also the experimental solubility data of L-Valine and L-Proline were successfully correlated with the thermodynamic relation mentioned in the previous work.