• Title/Summary/Keyword: $ZnBr_2$

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Study on the Electrolyte for Zn-Br Redox Flow Battery (Zn-Br 레독스 흐름 전지용 전해액에 관한 연구)

  • Choi, Ho-Sang;Oh, Yong-Hwan;Ryu, Cheol-Hwi;Hwang, Gab-Jin
    • Journal of Hydrogen and New Energy
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    • v.24 no.4
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    • pp.347-352
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    • 2013
  • Four types of electrolyte were tested for the application as an electrolyte in the Zn-Br redox flow battery. Electrolyte was consist of $ZnBr_2$ (electrolyte number 1), $ZnBr_2+KCl$ (electrolyte number 2), $ZnBr_2+KCl+NH_4Br$ (electrolyte number 3) and $ZnBr_2+KCl+EMPBr(C_7H_{16}BF_4N)$ (electrolyte number 4). The each electrolyte property was measured by CV (cyclic voltammetry) method. The different between the potential of anodic and cathodic maximum current density in a CV experiment (${\Delta}E_P$) was 0.89V, 0.89V, 1.06V and 0.61V for the electrolyte number 1, 2, 3 and 4, respectively. The electrolyte involved KCl increased conductivity which was appeared by anodic and cathodic maximum current density in a CV experiment. It was estimated that the electrolyte of number 3 ($ZnBr_2+KCl+NH_4Br$) and number 4 ($ZnBr_2+KCl+EMPBr$) could be suitable as an electrolyte in the Zn-Br redox flow battery with non-appeared bubble, non-Br formation and high anodic-cathodic maximum current density.

Cd(II) and Zn(II) Complexes Containing N,N'-Bidentate N-(Pyridin-2-ylmethylene)cyclopentanamine: Synthesis, Characterisation and Methyl Methacrylate Polymerisation

  • Song, Yujin;Kim, Dongil;Lee, Ha-Jin;Lee, Hyosun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.10
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    • pp.2929-2934
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    • 2014
  • The reaction between $[CdBr_2{\cdot}4H_2O]$ and anhydrous $[ZnCl_2]$ with N,N'-bidentate N-(pyridin-2-ylmethylene)-cyclopentanamine (impy) in ethanol yields dimeric $[(impy)Cd({\mu}-Br)Br]_2$ and monomeric $[(impy)ZnCl_2]$ complexes, respectively. The X-ray crystal structure of Cd(II) and Zn(II) complexes revealed that the cadmium atom in $[(impy)Cd({\mu}-Br)Br]_2$ and zinc in $[(impy)ZnCl_2]$ formed a distorted trigonal-bipyramidal and tetrahedral geometry, respectively. Both complexes showed moderate catalytic activity for the polymerisation of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO), with polymethylmethacrylate (PMMA) syndiotacticity of about 0.70.

Effect of Cadmium-contaminated Brown Rice Diet on Accumulation of Heavy Metal in Rats (카드뮴 오염 현미 섭취에 의한 랫드의 체내 중금속 축적)

  • Kim, Jae-Young;Im, Hyo-Bin;Kim, Seong-Jo;Baek, Seung-Hwa
    • Journal of Food Hygiene and Safety
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    • v.27 no.2
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    • pp.133-140
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    • 2012
  • Movement and accumulation of cadmium in male Sprague-Dawley rats, fed with brown rice from nearby Janghang smeltery area were investigated. The rat fed with five different cadmium level diets made with Cd-polluted during 12 weeks. The brown rice-polluted with 0.87 ppm Cd (PBR) was sampled from products in the Janghang smeltery area. Diets of brown rice group were brown rice (BR, 0.002 ppm Cd), each 50% of BR and PBR (BR+PBR 50%, 0.44 ppm Cd) and PBR (PBR 100%, 0.87 ppm Cd). To compare with BR+PBR 50%, the another group diet composed the feed (FE, 0.002 Cd ppm) and each 50% of FE and PBR (FE+PBR 50%, 0.44 ppm Cd). Accumulation of Cd, Zn and Cu in blood, liver and kidney rats was measured by GF-AAS. The weight gain in BR groups and FE groups were different 0.22-0.26 and 1.08-1.26 g/day, respectively. Daily intake cadmium was 10.77 and 22.36 ${\mu}g/rat$ in BR+PBR 50% and PBR 100%, and 8.83 ${\mu}g/rat$ in FE+PBR 50%. Cadmium contents in diets were higher, and total intake of the heavy metals was more increased on the whole. Weights of liver and kidney in FE+PBR 50% group was 2.64 and 2.27 folds higher than those in BR+PBR 50% group. Cadmium contents in blood were increased with intake of BR diet, but Zn and Cu were decreased with them. In the diet groups with the same Cd concentration, Cd content of FE+PBR 50% was higher 1.27 times than that of BR+PBR 50%. In the diet group of BR, BR+PBR 50%, and PBR 100%, the increase of Cd concentration was significantly different to the increase of Cd content in the livers. In the same condition of Cd concentration, Cd contents were higher in the BR+PBR 50% group. In the diet groups of BR, BR+PBR 50%, and PBR 100%, the increase of Cd content in the kidneys led to the increase of Zn and Cu contents. In the same condition of Cd concentration, the diet group with the addition of BR was shown to be 3.11 times higher than with the addition of FE. In view of the results so far achieved, It was closely related with Cd, Zn, and Cu content.

Electrochemical Behavior of Zn(II)-Bilirubin Complex in N,N-Dimethylformamide (N,N-Dimethylformamide 용액 중에서 Zn(II)-Bilirubin 착물의 전기화학적 거동)

  • Zun-Ung Bae;Heung-Lark Lee;Tae-Myung Park;Moo-Lyong Seo
    • Journal of the Korean Chemical Society
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    • v.37 no.7
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    • pp.672-676
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    • 1993
  • The complexation of bilirubin with zinc(II) and copper(II) ions was studied spectrophotometrically. In the zinc(II)-bilirubin (Zn-BR) system, complex is formed, but the copper(II) ion oxidizes bilirubin to biliverdin and then to the further oxidation products. The electrochemical reduction behavior of ZN-BR complex has been investigated with DC polarography and cyclic voltammetry. The three polarographic waves were obtained for the reduction of ZN-BR complex in DMF solution. Thde reduction current of the third wave was diffusion current, but that of the first and the second waves contained a little kinetic current.

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Characteristics of the Zn-Br Redox Flow Battery using the Different Electrolyte and Membrane (전해액과 격막에 따른 Zn-Br 레독스 흐름 전지의 특성)

  • CHOI, HO-SANG;OH, YONG-HWAN;RYU, CHEOL-HWI;HWANG, GAB-JIN
    • Journal of Hydrogen and New Energy
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    • v.27 no.4
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    • pp.365-371
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    • 2016
  • Cell performance of the Zn-Br redox flow battery (ZBRFB) using two different type's membrane (Nafion117 and SF-600) was evaluated at $20mA/cm^2$ of current density in 1M (mol/L) $ZnBr_2$ + 2M KCl + 0.3M EMPBr(1-ethyl-1-methyl pyrrolidinium bromide) electrolyte. The average energy efficiencies of ZBRFB were 74.9% and 74.7% for Nafion117 and SF-600, respectively. The electrolyte added the 1-ethyl-3-methylimidazolium dicyanamide (EMICA) as an additive was tested for the electrolyte in ZBRFB using SF-600 at $30mA/cm^2$ of current density. An average energy efficiency of the ZBRFB was 74.5% and 77.4% for the electrolyte non-added EMICA and added 1wt% of EMICA, respectively. ZBRFB using the electrolyte added EMICA was showed the higher performance than that using the electrolyte non-added EMICA.

Synthesis and Properties of Polydentate Schiff Base Ligands having $N_nO_2$ (n=3~5) Donor Atoms and Bromine Substituent and their Transition Metal Complexes (여러자리 질소-산소계 시프염기 리간드와 전이금속착물의 합성 및 전기화학적 특성)

  • Kim, Sun-Deuk;Shin, Yun-Yeol;Park, Sung-Woo
    • Analytical Science and Technology
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    • v.11 no.6
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    • pp.440-447
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    • 1998
  • Polydentate Schiff base ligands 5-Br-BSDT(bis(5-bromosalicylaldehyde)diethylenetriamine) having $N_3O_2$ atoms, 5-Br-BSTT(bis(5-bromosalicylaldehyde)triethylenetetramine) having $N_3O_2$ atoms, 5-Br-BSTP(bis(5-bromosalicylaldehyde)tetraethylenepentamine) having $N_3O_2$ atoms were synthesized. Stability constants of the complexes between these ligands and the metal ions such as Cu(II), Ni(II) and Zn(II) were measured in DMSO by a polarographic method. It was observed that all metal(II) ions employed in this study formed 1 : 1 complexes with Schiff base ligands. Stability constants for the ligands were in the order of Cu(II)>Ni(II)>Zn(II), and for complex formation were in the order of 5-Br-BSTP>5-Br-BSTT>5-Br-BSDT according to the increasing in the number of donor atoms. Both enthalpy and entropy changes are obtained in negative valves. Exothermicity for the complex formation indicated tight binding between the ligands and metal ions. The negative entropy change would be related to the fact that solvent molecules are strongly interacting with the metal complexes.

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Studies on Marine Sediments of the Korean Seas. I. Concentrations and Distributions of Some Ceochemical Elements in Sediments from the Sea off Eastern Korea (한국근해의 해저토에 관한 연구 I. 동해 해저토의 지화학적 성분의 함량과 분포)

  • Choe, Sang
    • 한국해양학회지
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    • v.1
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    • pp.1-15
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    • 1971
  • Some major and minor geochemical contents, such as Zr, Br, Ni, Sr, Zn, Mn, Ti and Fe, of ninety-seven sediment samples from the sea off eastern Korea have been analyzed by the fluorescence spectrometric techniques. Concentrations of elements showed 22-962ppm Zr(averaging 194.4ppm), tr-220 ppm Br(averaging 138.2ppm), 31-141ppm Ni(averaging 89.1ppm), 118-3,494ppm Sr(averaging 448.6ppm) 27-134ppm Zn(averaging 92.5ppm), 38-1,043ppm Mn(averaging 664.2ppm), 0.04-0.42% Ti(averaging 0.29%) and 0.57-4.02% Fe(averaging 2.76%). The ratios of Zn/Ti 10$\^$3/, An/Fe 10$\^$3/ and Ti/Fe were 0.27-6.43(averaging 3.27), 2.25-7.76 (averaging 3.46) and 0.04-0.18(averaging 0.11), respectively. From the results of geochemical analyses of sediments from the sea off eastern Korea represented the different types of sediment pattern are considered between the southern part and the northern part of the sea. The bottom sediments of the southern part were characterized with higher Sr and lower Zn, Br contents; higher Zr and lower Br contents; lower Br and lower Zn, Ti and Fe contents; and lower Zn and lower Ti and Fe contents.

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Study on a Separator for the Zn-Br Redox Flow Battery (Zn-Br 레독스 흐름 전지용 격막에 관한 연구)

  • Na, Il-Chae;Jo, Hong-Sic;Ryu, Cheol-Hwi;Hwang, Gab-Jin
    • Membrane Journal
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    • v.24 no.5
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    • pp.386-392
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    • 2014
  • Two commercial membranes (porous membrane and cation exchange membrane) were evaluated as a separator in the Zn-Br redox-flow battery (ZBRFB). The performance properties of ZBRFB were test in the current density of $20mA/cm^2$. The electromotive forces (OCV at SOC 100%) of ZBRFB using SF-600 (porous membrane) and Nafion 117 (cation exchange membrane) were 1.87 V and 1.93 V, respectively. The cycle performance of ZBRFB using each membrane was evaluated during 7 cycles. The performance of ZBRFB using SF-600 membrane was 89.76%, 83.46% and 74.88% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of ZBRFB using Nafion117 membrane was 97.7%, 76.33% and 74.56% for average current efficiency, average voltage efficiency and average energy efficiency, respectively.

Thermodynamic Analysis of a Double-Effect Absorption Heating System Using Water-LiCl-$CaCl_2-Zn(NO_3)_2$ Solution at Solar Evaporator Heating (LiCl-$CaCl_2-Zn(NO_3)_2$ 수용액을 사용하는 흡수 2중효용 시스템에서 태양열을 증발기 열원으로 사용하는 난방기의 열역학적 해석)

  • Won, Seung-Ho
    • Journal of the Korean Solar Energy Society
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    • v.27 no.3
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    • pp.87-94
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    • 2007
  • In this paper, with water-LiCl-$CaCl_2-Zn(NO_3)_2$ mixture which utilizes solar energy at the evaporator heat source, a thermodynamic analysis was performed to provide design data for a double-effect absorption heating system. A comparative study of the water-LiCl-$CaCl_2-Zn(NO_3)_2$ mixture against the water-LiBr pair was conducted by a computer simulation. The computer simulation is based on mass, material and heat balance equations for each part of the system. Coefficients of performance and flow ratios for effects of different operating temperatures are investigated. It is found that the heating COP is higher for the water-LiCl-$CaCl_2-Zn(NO_3)_2$ mixture than for the water-LiBr pair, and FR is lower for the former.