• Title/Summary/Keyword: ionic species

Search Result 280, Processing Time 0.022 seconds

Charging of an Ionic Liquid Droplet in a Dielectric Medium (비전도성 매질 내 이온성 액체 액적의 충전 현상)

  • Im, Do Jin
    • Clean Technology
    • /
    • v.20 no.4
    • /
    • pp.354-358
    • /
    • 2014
  • Ionic liquid (IL) is a salt presents in a liquid form at room temperature. Recently, it attracts huge attention due to its possibilities as a clean solvent, electrolyte, and catalyst. In the present work, the charging behavior of six different ILs were investigated using droplet contact charging phenomenon in a dielectric medium. Basically, the charging of an IL droplet can be explained by a perfect conductor theory. However, there were several different features depending on the species of ions of ILs, which requires rigorous molecular level modeling of charge transport through electrochemical reaction of IL. We hope the present results contribute to build up fundamental understanding of electrochemical charge transport of IL.

Studies on Silk Fibroin Membranes(III) ―Permselectivity of Alkali Metal Chlorides through Silk Fibroin Membrane― (Silk Fibroin 막에 관한 연구(III) ―Silk Fibroin 막의 Alkali Metal Ion선택투과성―)

  • Choi, Hae Wook;Sung, Woo Kyung;Park, Soo Min;Kim, Kyung Hwan
    • Textile Coloration and Finishing
    • /
    • v.6 no.4
    • /
    • pp.72-76
    • /
    • 1994
  • The permselectivity of alkali metal chlorides through silk fibroin membrane was investigated at $25^{\circ}C$: The Permeability coefficients were found to increase in a sequence of LiCl < NaCl < KCl < CsCl. This sequence was explained by considering the partition and the hydrophilic membrane. The dependence of the permeability on the salts concentration was interpreted by means of TMS theory. The ionic mobility ratio of alkali metal chlorides through this membrane decreased with the increase of the Stokes radius. The Effectiveness of the charged density was found to depend on the ionic species. The greater the Stokes radius the larger the effective charge density of membrane.

  • PDF

Interaction between a Flame and a Non-thermal Plasma (화염과 저온플라즈마의 상호작용에 관한 연구)

  • Cha, Min-Suk;Lee, Sang-Min;Kim, Kwan-Tae;Chung, Suk-Ho
    • 한국연소학회:학술대회논문집
    • /
    • 2002.06a
    • /
    • pp.179-184
    • /
    • 2002
  • Interaction between flames and non-thermal plasmas of DBD type has been experimentally investigated. Vigorous streamers were observed under flame conditions because of the increase of reduced field (electrical) at high temperature as well as the seeding of free electrons and ions generated inside the flame. Flame lengths were significantly shortened as the applied voltage increased on account of intense mixing by ionic winds and soot-induced flows. Flame luminosities severely decreased under plasma conditions, which means the reduction of soot, since the residence time was reduced because of the flame shortening. Temperature and major species concentrations measured by FTIR were not changed despite the plasma generation. which shows overall chemistries were not affected by non-thermal plasmas.

  • PDF

Application of Thermodynamic Models for Analysis on SI Thermochemical Hydrogen Production Process (SI 열화학 수소 생산 공정의 분석을 위한 열역학 모델의 적용)

  • Lee, Jun Kyu;Kim, Ki-Sub;Park, Byung Heung
    • Journal of Institute of Convergence Technology
    • /
    • v.2 no.2
    • /
    • pp.30-34
    • /
    • 2012
  • The SI thermochemical cycle process accomplishes water splitting through distinctive three chemical reactions. We focused on thermodynamic models applicable to the process. Recently, remarkable models based on the assumed ionic species have been developed to describe highly nonideal behavior on the liquid phase reactions. ElecNRTL models with ionic reactions were proposed in order to provide reliable process simulation results for phase equilibrium calculations in Section II and III. In this study, the current thermodynamic models of SI thermochemical cycle process were briefly described and the calculation results of the applied ElecNRTL models for phase equilibrium calculations were illustrated for binary systems.

  • PDF

Effect of Flow Rate on the Continuous Cycling Electrolytic Treatment Process for Silver Ion Containing Wastewater (은 함유 폐수의 연속 순환 전해처리 시 유량변화가 회수 공정에 미치는 영향)

  • Chung, Won-Ju;Kim, Dong-Su
    • Journal of Korean Society on Water Environment
    • /
    • v.23 no.5
    • /
    • pp.577-580
    • /
    • 2007
  • The influence of flow rate has been investigated on the treatment efficiency of continuous cycling electrolytic process employing artificial and actual photographic wastewater which containing silver ion. For artificial wastewater, the treatment efficiency of process was found to rise ca. three times when the flow rate of wastewater was increased from 3 mL/min to 15 mL/min. The process efficiency was doubled under the same condition regarding actual wastewater. The effect of flow rate on the treatment efficiency was observed to be altered according to the metal ionic form and solution composition. The coefficient of mass transfer was estimated using model equation, which verified that the raised treatment efficiency at higher flow rate was due to the increased mobility of ionic species.

Surface Conductance Modulation of Single-Walled Carbon Nanotubes and Effects on Dielectrophoresis (단일벽 탄소나노튜브의 표면 전도도 조절 및 유전영동에 대한 영향)

  • Hong Seung-hyun;Jung Se-hun;Kim Young-jin;Choi Jae-bong;Baik Seunghyun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.30 no.2 s.245
    • /
    • pp.179-186
    • /
    • 2006
  • Dielectrophoresis has received considerable attention for separating nanotubes according to electronic types. Here we examine the effects of surface conductivity of semiconducting single-walled carbon nanotubes (SWNT), induced by ionic surfactants, on the sign of dielectrophoretic force. The crossover frequency of semiconducting SWNT increases rapidly as the conductivity ratio between the particle and medium increases, leading to an incomplete separation of ionic surfactant suspended SWNT at an electric field frequency of 10 MHz. The surface charge of SWNT is neutralized by an equimolar mixture of anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant cetyltrimenthylammonium bromide (CTAB), resulting in negative dielectrophoresis of semiconducting species at 10 MHz. A comparative Raman spectroscopy study shows a nearly complete separation of metallic SWNT.

Sorption of Radioactive Cobalt and Ruthenium on Soil Minerals (방사성 코발트 및 루테늄의 토양 흡착)

  • Lee, Byung-Hun;Hands, J.D.
    • Journal of Radiation Protection and Research
    • /
    • v.15 no.2
    • /
    • pp.7-16
    • /
    • 1990
  • The sorption of radioactive cobalt and ruthenium on alumina, silica gel, zeolite 3A, kaolin and Na-bentonite has been studied as a function of pH. nuclide concentration and ionic strength. Retardation factor for cobalt and ruthenium on soil minerals was determined through porosity measurement. Hydrolysed species, cobalt and ruthenium interact with solid surfaces by physical adsorption processes. Freundlich sorption isotherms for cobalt and ruthenium are effectively linear. The sorption decreases with increasing ionic strength for cobalt and ruthenium. The effect of increasing porosity on the retardation factor countered the effect of a significant increase in the distribution coefficient.

  • PDF

Separation of Lipases Using Reversed Micelles (역미셀을 이용한 리파아제의 분리)

  • 최평호;류희욱이태호장용근
    • KSBB Journal
    • /
    • v.6 no.4
    • /
    • pp.337-344
    • /
    • 1991
  • The liquid-liquid extraction of lipase A from Candide cylindracea and lipase B from porcine pancrease was carried out using reversed micellar organic solvents. Effects of various factors such as ionic strength, pH, and species and concentration of surfactant, on lipase solubilization were studied. A cationic surfactant cetyl-trimethyl ammonium bromide (CTAB) in isooctane/nhexanol(1:1) was found to be an effective solvent and its optimum concentration was 50 mM. KCl among various salts tested was the most effective and the efficiency of solubilization of lipase increased with decreasing the ionic strength of salts. The maximum activity and solubiliz ation of protein were obtained at pH 8. The stripping efficiency has a maximum value at pH 4 and increases with KCl concentration in the range of 0.2∼1.0 M. After the solubilization and stripping, the overall recovery efficiency of mass and specific activity of lipases was 62% and 66%, respectively.

  • PDF

Prediction of the Dynamic Adsorption Behaviors of the Uranium and Cobalt Ions in a Fixed Bed by Surface Modified Activated Carbon (표면개질 활성탄을 이용한 고정층에서 우라늄 및 코발트 이온의 동적 흡착거동 모사)

  • Geun-IL Park;Jung-Won Lee;Kee-Chan Song;In-Tae Kim;Kwang-Wook Kim;Myung-Seung Yang
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.1 no.1
    • /
    • pp.81-92
    • /
    • 2003
  • In order to predict the dynamic behaviors of uranium and cobalt in a fixed bed at various influent pH values of liquid waste, the adsorption system is regarded as a multi-component adsorption between each ionic species in the solution. Langmuir isotherm parameters of each species were extracted by incorporating equilibrium data with the solution chemistry of the uranium and cobalt using IAST. Prediction results were in good agreement with the experimental data, except for a high concentration and pH. Although there was some limitations in predicting the cobalt adsorption, this method may be useful in analyzing a complex adsorption system where various kinds of ionic species exist in a solution.

  • PDF

Gallium(III) Ion Hydrolysis under Physiological Conditions

  • Hacht, Brahim
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.2
    • /
    • pp.372-376
    • /
    • 2008
  • The hydrolysis of gallium(III) has been studied using potentiometric techniques under physiological conditions of temperature 37 C and ionic strength 0.15 moldm-3 NaCl and at different metal ion concentrations. Changes in pH were monitored with a glass electrode calibrated daily in hydrogen ions concentrations. The titration data within the pH range of 2.5-9.99 were analyzed to determine stability constants of hydroxide species using the SUPERQUAD program. Several different species were considered during the calculation procedure and the following hydroxides have been characterized: Ga(OH)3, Ga(OH)4- Ga3(OH)112-, Ga4(OH)11+ and Ga6(OH)153+. Speciation calculations based on the determined constants were then used to simulate the species distribution.