• Title/Summary/Keyword: Ion-Exchange

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Effect of ECR-Ion Milling on Exchange Biasing in NiO/NiFe Bilayers

  • D.G. Hwang;Lee, S. S.;Lee, K. H.;Lee, K. B.;Park, D. H.;Lee, H. S.
    • Journal of Magnetics
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    • v.5 no.1
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    • pp.23-25
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    • 2000
  • We have investigated the effects of Ar and$O_2$-ion milling on the exchange coupling field ($H_{ex}$) and coercive field ($H_c$) at the interfaces between substrates and NiO/NiFe films, to understand the exchange biasing mechanism. The $O_2$-ion milling was successfully performed by means of the electron cyclotron resonance (ECR) process. We found that the local roughness gradient of the NiO surface increased by $O_2$-ion milling. The ratio of $H_{ex}/H_c$ increased from 0.87 to 1.77, whereas $H_c$ decreased by almost a half as a results of the ion milling. The decrease in $H_c$could be interpreted as due to the refinement of magnetic domain size, which arose from the increase of the local roughness gradient of the NiO surface. The decrease in low $H_c$, and increase in $H_{ex}$ in NiO spin valves by ECR-ion milling are in the right direction far use in magnetoresistance (MR) heads.

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A Study on the Adsorption of Uranium(VI) Ion Using Ion Exchange Resin (이온 교환수지를 이용한 우라늄(VI) 이온의 흡착에 관한 연구)

  • 강영식;김준태
    • Journal of environmental and Sanitary engineering
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    • v.15 no.4
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    • pp.114-122
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    • 2000
  • Several new ion exchange resins have been synthesized from chloromethyl styrene-1,4-divinylbenzine with 1%, 2%, 5% and 105-crosslink and macrocyclic ligands of cryptand type by interpolymerization method. The adsorption characteristics and the pH, time, solvents and concentration dependence of the adsorption of uranium ion by this resins were studied. The resins were very stable in both acidic and basic media and have good resistance to heat at $300^{\circ}C$. The uranium ion are not adsorbed on the resins below pH 3.0, but the power of adsorption of it increased rapidly above pH 4.0. The optimum equilibrium time for adsorption of uranium ion was two hours and adsorptive power decreased in proportion to crosslink size of the resins and order of dielectric constants of solvents used and the adsorption for uranium ion was bin the order of $OdienNtn-H_4$ > $OtnNen-H_4$ > $OtnNen-H_4$ > $OenNen-H_4$.

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The Effects of Tin in Bottom Surface to Ion Exchange of Float Glasses (Float 판유리에 있어서 바닥면의 Tin성분이 이온교환에 미치는 영향)

  • 이동인;이용근;이희수
    • Journal of the Korean Ceramic Society
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    • v.27 no.6
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    • pp.763-768
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    • 1990
  • The gradient and depth of tin at the side of glasses by float process were measured. The effects of tin to ion exchanged of glasses in the molten salt of KNO3 and AgNO3 were presented by means of Ag+ ion penetration depth, diffusion coefficient variation, spectral transmittance and color coordinates. The diffusion coefficient of Ag+ ion of tin side was higher than air side, and the activation energy of tin side was 0.2-0.6Kcal/mole lower than air side. Therefore Ag+ ion penetration depth of tin side is 2-10$\mu\textrm{m}$ deeper, hence it can be seen that tin promote Ag+ ion diffusion. The same treatment of ion exchange, reddish-brown oflong wavelength in case of tin present, yellowish-amber of short wavelength in case of tin absence were revealed.

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Studies on the Preparation of the Poly(vinyl alcohol) ion Exchange Membranes for Direct Methanol Fuel cell (폴리비닐알콜을 이용한 직접메탄을 연료전지용 이온교환막 제조에 관한 연구)

  • 임지원;천세원;전지현;남상용
    • Membrane Journal
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    • v.13 no.3
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    • pp.191-199
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    • 2003
  • Cation exchange polymer electrolyte membrane for the application of direct methanol fuel cell (DMFC) was studied. Poly(vinyl alcohol)(PVA) well known as a methanol barrier in pervaporation separation was used fur the base materials and poly(acrylic acid)(PAA) was used for the crosslinking agent with various concentration. Methanol permeability, ion conductivity, ion exchange capacity, water contents and fixed ion concentration of the membranes were investigated to evaluate the performance of the fuel cell electrolyte membrane. Methanol permeability and ion conductivity of the membranes were decreased with increasing PAA content and were increased over 15% of PAA content. These phenomena would be explained with the introduction of hydrophilic crosslinking agent. The membranes with 15% content of PAA showed methanol permeability of $6.49{\times}10^{-8}/cm^2/s,\; 2.85{\times}10^{-7}CM^2/s$ at $25^{\circ}C,\; 50^{\circ}C$ of operating temperatures, respectively. ion conductivities of the membrane were $2.66{\times}10^{-3}\;S/cm,$ $9.16{\times}10^{-3}\;S/cm$ at $25^{\circ}C,\; 50^{\circ}C$ of operating temperatures, respectively. ion exchange capacity, water content and fixed ion concentration of the membrane were revealed 1.32 meq/g membrane,0.25 g $H_2$O/g membrane and 5.25 meq/g $H_2O$, respectively.

A Study of Salt's Effects on Cooked Food (각종 식염의 조리효과에 관한 연구)

  • 문수재
    • Journal of the Korean Home Economics Association
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    • v.17 no.1
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    • pp.22-28
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    • 1979
  • The phyio-chemical properties of Ion exchange salt, crude salt, particaly refined salt, and Isoized salt were determined. The basic amount of salt used in cooking were standardized . Acceptabilities as to the taste and saltiness of food prepared with the standard amounts of various kinds of salt were compared. Whereupon, the following conclusion was obtained. 1) Crude salt showed 12.23 per cent water content, the highest among the kinds of salt examined, while particaly refined salt had 2.53% water content. Refined salt, Ion exchange salt, and Iodized salt showed 0.36%, and 0.28%, respectively. 2) Where the same amount of salt was dissolved in the same amount of water, crude salt and partialy refined salt were dissolved twice as Ion exchange salt of fine-grain form, refined salt, and Iodized salt. In actual cooking, Ion exchanges salt and refined salt are used only half as much as raw salt, and it can be said that the time required for dissolving salt is the same. 3) The comparison between content and weight of various kinds of salt showed that the weights of Ion exchange salt, Iodized salt, and refined salt were two times as heavy as crude salt and partialy refined condition of same content. 40 The threshold concentration of salt is the sensed degree of saltiness. Different concentrations were recorded for various for various kinds of salt, the threshold concentration of Ion exchanges salt showed the lowest degree of 0.05, while that of partialy refined salt was 0.09 equivalent to 1.8 times that of the former. 5) Experimental cooking involving various kinds of salt indicated that where salt was used accurately, soup, vegetables, kimchi, and soybean sauce which were prepared with Ion exchanges salt showed the best acceptability , but no statistical differences could be noted among sarious kinds of salt used in preparing those foods.

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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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The Effect of Organic Acids in Decontamination Solution on Ion Exchange of Metal Ions (제염용액내 유기산이 금속이온 이온교환에 미치는 영향)

  • Yang, Yeong-Seok;Kang, Young-Ho;Jheong, Gyeong-Rak
    • Applied Chemistry for Engineering
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    • v.4 no.1
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    • pp.171-177
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    • 1993
  • In decontamination process to remove radioactive materials of reactor cooling system, the metal ions dissolved by organic acids in decontamination solution are separated by use of ion exchange resin in the column. However, organic acids in decontamination solution decrease the apparent affinity of the resin to metal ions. In light of this, some experiments were carried out on the Amberlite IRN-77 cation resin with cobalt and iron to gain a better understanding of the complexation effects on the ion exchange process. Experimental results showed that EDTA among organic acids used as chemical decontaminants predominantly caused reduction of ion exchange capacity of cobaltous ion to resin since this reagent formed the complex with the cobaltous ion stronger than that with the ferrous ion. In contrast, the effects of oxalic acid and citric acid were found to be negligible. And, single and two-component nonlinear equilibrium relationships of the metal ions were established using experimental data.

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Preparation and Characteristics of Heterogeneous Cation Exchange Membrane : 1. Mixing Ratio of Matrix and Ion Exchange Resin (PE계 불균질 양이온 교환막의 제조와 특성:1.결합제와 이온교환수지의 비율에 따른 영향)

  • Yang, Hyun S.;Cho, Byoung H.;Kang, Bong K.;Lee, Tae W.
    • Applied Chemistry for Engineering
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    • v.7 no.6
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    • pp.1132-1141
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    • 1996
  • Heterogeneous cation exchange membrane(HCEM) was prepared with LLDPE(Linear Low Density Poly-ethylene) as binder, powdered cation exchange resins($diameter{\leq}149{\mu}m$) as ion-exchange material and glycerol as additive for electrodialysis and electrodeionization system. The weight ratio of (binder/ion exchange)/glycerol was (60%/40%)/5%, (55%/45%)/5%, (50%/50%)/5% and (40%/60%)/5%. The characterization of prepared HCEM was evaluated on mechanical, electrochemical, morphology and ion permeable properties. It was compared with commercial membrane. Electrochemical properties of HCEM of (50%/50% )/5% were very similar to value of IONPURE(commercial membrane), in which ion exchange capacity, ion transfer number and membrane resistance were to be 1.733meq/g, 0.96 and $16.08{\Omega}/cm^2$, respectively. Ion permeability of the membrane was better than that of IONPURE membrane. Compared with IONPURE membrane, the HCEM had a higher tensile strength and lower elongation and modulus, in which HCEM had tensile strength of $62.33kg/cm^2$, elongation of 87.42% and modulus of $658.53kg/cm^2$. The HCEM of (50%/50% )15% was optimum combination.

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Recovery of High Purity Tin from Waste Solution of the Tin Plating by Ion-exchange and Cyclone-electrowinning (주석도금폐액으로부터 이온교환 및 사이클론 전해채취를 이용한 고순도 주석의 회수)

  • Kang, Yong-Ho;Shin, Gi-Wung;Ahn, Jae-Woo
    • Resources Recycling
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    • v.25 no.4
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    • pp.42-48
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    • 2016
  • A research for the recovery of the metal with high purity from the waste tin plating solution was carried out. First, tin plating waste solution was tested to remove the organic substances and metallic impurities such as Fe, Zn, Na etc. using ion exchange resin having iminodiacetic functional groups (Lewatit TP 207). Second, the tin solution was purified to obtain the high purity tin solution using ion exchange resin having ethylhexyl-phosphate functional groups (Lewatit VPOC 1026). Finally, 99.98% of the high purity of tin metal can be recovered from the purified solution by cyclone type electrowinning method.

Purification of a major protein with physiological activities from Panax ginseng C. A. Meyer (고려인삼(Panax ginseng C. A. Meyer)에서 생리활성을 보이는 25 kDa 주요단백질 (GMP)의 분리정제)

  • Kwon, Taek-H.;Oh, Sei-R.;Park, H.;Kim, Kyung-H.
    • Applied Biological Chemistry
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    • v.41 no.6
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    • pp.410-413
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    • 1998
  • The major protein (GMP) from the roots of Panax ginseng C. A. Meyer was purified, using gel filtration and ion exchange chromatography followed by reversed-phase and ion exchange FPLC. Staining analysis indicated that the protein has a carbohydrate moiety, which was also shown by band shift experiments using various glycosidases. Electrophoretic and gel permeation studies showed that GMP has an apparent molecular weight of 63 kDa composed of possibly two subunits of 25 kDa containing carbohydrate moiety. GMP showed an anticomplementary activity on the hemolysis of red blood cells, which is a screening tool for inflammation mediator search.

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