• Title/Summary/Keyword: co-anion

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A Study on the Contamination of D.I. Water and its Effect on Semiconductor Device Manufacturing (초순수의 오염과 반도체 제조에 미치는 영향에 대한 연구)

  • Kim, Heung-Sik;Yoo, Hyung-Won;Youn Chul;Kim, Tae-Gak;Choi, Min-Sung
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.11
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    • pp.99-104
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    • 1993
  • We analyzed the D.I. water used in wet cleaning process of semiconductor device manufacturing both at the D.I. water plant and at the wafer cleaning bath to detect the impurity source of D.I. water contamination. This shows that the quantity of impurity is related to the resistivity of D.I. water, and we found that the cleanliness of the wafer surface processed in D.I. water bath was affected by the degree of the ionic impurity contamination. So we evaluated the cleaning effect as different method for Fe ion, having the best adsoptivity on wafer surface. Moreover the temperature effect of the D.I. water is investigated in case of anion in order to remove the chemical residue after wet process. In addition to the control of D.I. water resistivity, chemical analysis of impurity control in D.I. water should be included and a suitable cleaning an drinsing method needs to be investigated for a high yielding semiconductor device.

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Synthesis and Characterization of New Intermetallic Compounds $M_3(AsTe_3)_2$ (M=Cr, Fe, Co)

  • 정진승;김현학;강석구;채원식;김돈;이성한
    • Bulletin of the Korean Chemical Society
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    • v.18 no.10
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    • pp.1105-1108
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    • 1997
  • The new amorphous intermetallic compounds, M3(AsTe3)2: M=Cr, Co, Fe, were synthesized by the precipitation reaction of the Zintl anion AsTe33- with the divalent transition metal halides in aqueous solution and analyzed by EDS equipped with SEM and PIXE. The empirical formula of the specimens was found to be Fe3.0As1.8Te5.9, Co3.0As2.1Te6.5, and Cr3.0As2.0Te6.9 by the quantitative elemental analysis. The dc specific resistivity of the materials was measured as a function of temperature in the range from 20 to 300 K, in which their resistivity of Cr3(AsTe3)2 was largely dependent on temperature, while those of Co3(AsTe3)2 and Fe3(AsTe3)2 were only slightly dependent on temperature. To characterize the spin glass state of the specimens, the ac and dc magnetic susceptibility were measured and it was found that Co3(AsTe3)2 and Fe3(AsTe3)2 undergo a transition to a spin glass state at 6 K and 38 K, respectively. Magnetization data are reported as both thermal remanent magnetization (TRM) and isothermal remanent magnetization (IRM) as a function of magnetizing field and temperature.

Sorption and Separation of Thiocyanate Gold and Silver Complexes and Determination of Gold by Diffuse Reflectance Spectroscopy

  • Danilenko, N.V.;Kononova, O.N.;Kachin, S.V.;Kholmogorov, A.G.;Dmitrieva, Zh.V.;Plotnikova, E.A.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.7
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    • pp.1019-1024
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    • 2004
  • The present paper is focused on simultaneous sorption concentration of gold (III) and silver (I) from thiocyanate solutions using high-selective anion exchanger AN-25 and subsequent separation of these ions at various concentrations of thiocarbamide (eluent). As a result, silver (I) ions are completely eluted from AN-25 and gold (III) ions remain in the resin phase and can be determined directly in the solid phase by diffuse reflection spectroscopy. It is proposed to use the sorption-spectroscopic method for Au(III) determination in aqueous solutions. The calibration curve is linear in the concentration range of 1-19 mg/L (sample volume is 10.0 mL) and the detection limit is 0.05 ${\mu}g/mL$. The presence of Cu(II), Co(II), Fe(II) do not hinder this determination. Au(III) was determined in industrial solutions.

Evaluation of Affecting Factors on the Ferrous Catalyzed Sodium Persulfate Oxidation for the Destruction of Organic Pollutant (과황산나트륨을 이용한 유기 오염물 산화와 영향인자 평가)

  • Yun, Yeobog;Park, Haimi;Ko, Sunghwan;Ko, Seokoh
    • Journal of Korean Society on Water Environment
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    • v.25 no.1
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    • pp.151-158
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    • 2009
  • The objective of this study was to determine on optimum ratio of oxidant and catalyst and to evaluate affecting factors such as anions and cations on persulfate oxidation of organic pollutant. Fe(II) activated the persulfate anion to produce a sulfate free radicals and thus effectively used to degrade the target organic pollutant in aqueous system. The chloride ions reacted with sulfate radical produced the $Cl^{\cdot}$ atom and had positive effects on the oxidation of organic pollutant at the initial stage. However, it was observed that chloride ions had the scavenging effects on the rate of oxidation of organic pollutant. Cations and some heavy metals were partly able to activate the persulfate anion to generate a sulfate free radical. However, high levels of cations inhibited the oxidation of organic pollutant.

Photocatalytic Decolorization of Dye usingUV/TiO2 and Fluidized Bed Reactor (UV/TiO2와 유동층 반응기를 이용한 안료의 광촉매 탈색)

  • Park Young-Seek
    • Journal of Environmental Science International
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    • v.13 no.10
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    • pp.921-928
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    • 2004
  • The photocatalytic decolorization of Rhodamine B (RhB) was studied using immobilized $TiO_2$ and fluidized bed reactor. Immobilized $TiO_2$(length: 1$\~$2 mm, width: 1$\~$3 mm, thickness: 0.5$\~$2 mm) onto silicone sealant was employed as the photocatalyst and a 30 W germicidal lamp was used as the light source and the reactor volume was 4.8 L. The effects of parameters such as the amounts of photocatalyst, initial concentration, initial pH, superficial velocity, $H_2O_2$ and anion additives. ($NO_3^{-},\;SO_4^{2-},\;Cl^{-},\;CO_3^{2-}$) The results showed that the optimum dosage of the immobilized $TiO_2$ were 87.0 g/L. Initial removal rate of RhB of the immobilized $TiO_2$ was 1.5 times higher than that of the powder $TiO_2$ because of the adsorption onto the surface of immobilized $TiO_2$ In the conditions of acidic pH, initial reaction rate was increased slowly and reaction time was shorted. The effect of anion type on the reaction rate was not much.

Anti-oxidative Activities of Commercial Edible Plant Extracts Distributed in Korea (국내 유통 중인 식용식물 추출물의 항산화효과)

  • Kim, Kyung-Bum;Yoo, Ki-Hwan;Park, Ha-Yan;Jeong, Jong-Moon
    • Applied Biological Chemistry
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    • v.49 no.4
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    • pp.328-333
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    • 2006
  • Many plant extracts are known to have antioxidative effects. However, their activities can be reduced or disappeared during mass production process. The purpose of this study is to compare antioxidative effects of edible plant extracts distributed in Korea. forty three kinds of edible plant extracts commercially available in Korea were selected and investigated for their total phenolics contents and antioxidative potentials(DPPH radical and superoxide anion radical scavenging activities). In contents of total phenolics, the commercial plant extracts from Artemisia annua(whole plant), Ilex paraguariensis(leaf, Silybum marianum(fruit and leaf, Ulmus pumila(bark), Coliolus versicolor(fruit), and Curcuma longa(root and stem) contained over 70 mg/g of powder, DPPH radical scavenging activities($SC_{50}$, 50% scavenging concentration) of A. annua, I. paraguariensis, Pinus densiflora(leaf),S. marianum, U. pumila, and C. longa were $53.96{\pm}0.81\;ppm,\;24.61{\pm}2.12\;ppm,\;35.96{\pm}1.11\;ppm,\;57.46{\pm}2.13\;ppm,\;55.25{\pm}1.65\;ppm\;and\;12.99{\pm}1.67ppm$, respectively, while that of positive control(vitamin C) was $3.86{\pm}0.81\;ppm$. $SC_{50}$ values against superoxide anion radical of A. annua, Cinnamomum zeylanicum(bark), I. paraguariensis, Rubus coreanus(fruit and leaf), Morus alba(leaf), P. densiflora, S. marianum, U. pumila, C. versicolor, C. longa, Perilla frutescens var. acuta(leaf), and H. sabdariffa(leaf and newer) were $53.21{\pm}1.83ppm,\;50.12{\pm}2.12ppm,\;5.59{\pm}0.84ppm,\;41.60{\pm}8.93ppm,\;20.19{\pm}0.97ppm,\;15.19{\pm}1.66ppm,\;21.20{\pm}1.88ppm,\;15.71{\pm}0.91ppm,\;55.48{\pm}2.42ppm,\;52.12{\pm}2.44ppm,\;23.80{\pm}1.98ppm\;and\;11.14{\pm}0.51ppm$, respectively($SC_{50}$ value of vitamin C: $9.61{\pm}0.93ppm$). In particular, both 1 paraguariensis and P. densiflora had high content of phenolics as well as high scavenging activities of DPPH radical and superoxide anion radical. Consequently, above two commercial extracts may be useful as a source of antioxidative nutraceutics.

Treatment of Simulated Soil Decontamination Waste Solution by Ferrocyanide-Anion Exchange Resin Beads (Ferrocyanide-음이온 교환수지에 의한 모의 토양제염 폐액 처리)

  • Won Hui Jun;Kim Min Gil;Kim Gye Nam;Jung Chong Hun;Park Jin Ho;Oh Won Zin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.1
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    • pp.41-47
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    • 2005
  • Preparation of ferrocyanide-anion exchange resin and adsorption test of the prepared resin on the Cs$^{+}$$ion were performed. Adsorption capability of the prepared resin on the Cs$^{+}$ion in the simulated citric acid based soil decontamination waste solution was 4 times greater than that of the commercial cation exchange resin. Adsorption equilibrium of the prepared resin on the Cs$^{+}$ion reached within 360 minutes. Adsorption capability on the Cs$^{+}$ion became to decrease above the necessary Co$^{2+}$ion concentration in the experimental range. Recycling test of the spent ion exchange resin by the successive application of hydrogen peroxide and hydrazine was also performed. It was found that desorption of Cs$^{+}$ion from the resin occurred to satisfy the electroneutrality condition without any degradation of the resin.

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Electrochemical Properties and Synthesis of Poly(ether)tailed Cobalt(II)bipyridine Complex (폴리(에테르)사슬이 결합된 Cobalt(II)bipyridine 착물의 합성과 전기화학적 성질)

  • Kim, II Kwang;Jun, II Chul;Murray, Royce W.
    • Analytical Science and Technology
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    • v.9 no.3
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    • pp.292-301
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    • 1996
  • The synthesis of poly(ether)tailed bipyridine complex as redox reaction probes has advanced attempts to interpret very slow diffusion and heterogeneous electron transfer. Diffusion coefficients as low as $1.5{\times}10^{-15}cm^2/s$ have been observed for the oxidation of neat $Co(bpy(ppgm)_2)_{3^-}(ClO_4)_2$ with $LiClO_4$ electrolyte. Heterogeneous electron transfer rate constants of materials were found to vary with diffusion coefficient. The decrease in k as the diffusion coefficient decreases was actually caused by the decreasing D. Diffusion coefficient for compound of strong ion pairing anion($ClO{_4}^-$) was much smaller than the diffusion coefficient for compound of weak ion pairing anion($CF_3COO^-$).

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Improvement on the Antioxidant Activity of Instant Noodles Containing Enzymatic Extracts from Ecklonia cava and Its Quality Characterization (감태 효소 추출물을 이용한 즉석 국수의 항산화성 개선 및 품질 특성)

  • Heu, Min-Soo;Yoon, Min-Seok;Kim, Hyung-Jun;Park, Kwon-Hyun;Lee, Jong-Hyun;Jo, Mi-Ran;Lee, Jung-Suk;Jeon, You-Jin;Kim, Jin-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.5
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    • pp.391-399
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    • 2010
  • This study was conducted to improve the antioxidative activity of instant noodles containing enzymatic extracts from Ecklonia cava (EEC). EEC has relatively better antioxidative activity than extracts from other indigenous plants in Jeju Island. The EEC (2.5 mg/mL) had 82.5% for the hydroxy radical, 78.4% for the DPPH radical, and 64.9% for the superoxide anion radical scavenging activities, and 65.2% for the cell viability (100 ${\mu}g/mL$). According to the texture of the dough, the DPPH free radical scavenging of uncooked instant noodles, sensory evaluation of cooked instant noodles, and turbidity of the cooking drip, the optimal EEC concentration was 1.8% for the instant noodles. The major amino acids in the instant noodles with EEC were glutamic acid (24.2%), proline (10.2%), valine (10.0%), and isoleucine (12.3%). The zinc and iron in the instant noodles were enhanced by adding 1.5-1.8% EEC. The antioxidant activity of instant noodles with EEC was 75.4% for the hydroxy radical, 74.1% for the DPPH radical, and 51.2 % for the superoxide anion radical scavenging activities.

Study on Separation of Heavy Metal Ions in A Neutral Macrocycle-Mediated Emulsion Liquid Membrane System

  • Moon-Hwan Cho;Hea-Suk Chun;Jin-Ho Kim;Chang-Hwan Rhee;Si-Joong Kim
    • Bulletin of the Korean Chemical Society
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    • v.12 no.5
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    • pp.474-477
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    • 1991
  • The preferential transport phenomena of neutral cation-anion moieties in neutral macrocycle-facilitated emulsion liquid membrane were described in this study. Emulsion membrane systems consisting of (1) aqueous source phase containing 0.001 M M($NO_3$)$_2(M=Mn^{2+},\;Co^{2+},\;Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Sr^{2+},\;Cd^{2+},\;and\;Pb^{2+})$ (2) a toluene membrane containing 0.01 M ligand $(DBN_3O_2$, DA18C6, DT18C6, TT18C6, HT18C6) and the surfactant span 80 (sorbitan monooleate) (3% v/v) and (3) an aqueous receiving phase containing $Na_2S_2O_3$ or $NaNO_3$ were studied with respect to the disappearence of transition metal ions from the source phase as a function of time. Cation transports for various two component or three component equimolar mixture of transition metal and $Cu^{2+}$ in a emulsion membrane system incorporating macrocyclic ligand (HT18C6) as carrier were determinded. $Cu^{2+}$ was transported higher rates than the other $M^{2+}$ in the mixture solution. Equilibrium constants for cation-source phase co-anion, cation macrocycle and cation-receiving phase reagent interaction are examined as parameters for the prediction of cation transport selectivities.