• Analytical Science and Technology
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• v.7 no.3
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• pp.271-276
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• 1994

A Na-cellulose adsorbent was prepared by treating Sigma S-5504 cellulose with 2M NaOH and examined the adsorption behavior between metal ions and Na-cellulose in aqueous solution with batch method. Considering ion exchange capacity of Na-cellulose, the adsorption ratio of the Na-cellulose to metals charge equivalent indicated that the adsorption result from ion exchanging between metal ions and Na-cellulose. The enthalpy for the metal adsorption on the Na-cellulose was calculated to -18kcal/mol, which value was compared to those of carboxymethylcellulose(CMC) and Dowex 50W-X8, these result suggested that the adsorption on Na-cellulose resulted from ion exchange adsorption.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.463-463
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• 2011

집속이온빔장치(Foucused Ion Beam)에서 사용하는 액체금속이온원(Liquid Metal Ion Source)은 고 전류밀도, 고 휘도, 낮은 에너지퍼짐 등 많은 장점이 있다. 대부분의 집속이온빔 장치에서 플라즈마 이온소스에 비해 빔의 직경이 작고 GFIS 보다 다루기 쉬워 액체금속이온원을 많이 사용하고 있다. 기존에 사용하던 액체금속이온원에 서프레셔라는 새로운 전극을 추가시켜 팁과 갈륨저장소, 서프레셔, 추출극 구조로 만들었다. 이 연구를 위해 RPA(Retarding Potential Analyser)를 제작 하였다. RPA는 두 개의 메쉬와 하나의 컬렉터로 이루어져 있으며, 액체금속이온과 플로팅 되어있는 RPA에 전압의 차이를 주기위해 베터리로 제작한 파워로 액체금속이온에 인가되는 전압에 + 90V, -90V까지 제어가 가능하게 만들었다. 본 연구에서는 서프레셔의 유무에 따른 액체금속이온원의 에너지 퍼짐에 대해 연구하였다. 추출극에 전압 변화를 주어 방출되는 전류를 5uA, 10uA, 15uA, 20uA로 변화시켜가며 RPA에서 측정되는 전류를 가지고 전류-전압의 관계를 보았고, 에너지 퍼짐정도를 알았다. 마찬가지로 서프레셔에 전압 변화를 주어 전류-전압 관계, 에너지 퍼짐정도를 알았다.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.1-5
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• 2000

We have investigated dielectric properties of IMI-O LB films for the effect of complex concentration by electrical conductivity, dielectric constant and dielectric relaxation time at different frequencies. In the surface pressure-area$\pi$-A) isotherms for the increase of $FE^{3+}$ concentration, the molecular area was expanded with $FE^{3+}$concentration increase by electrostatic repulsion between the polymer chains and hydrophobic increase of ionic strength. In the I-V characteristics, it is found that the limiting area has effects on the change of conductivity And, the dielectric relaxation time decreased for increase of the $FE^{3+}$concentration.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.122-128
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• 1994

Macrocyclic ligand has been known to selectively bind with metal ions so that ability applied for the transport of metal ions across the emulsion liquid membrane in this study. The metal ions are transproted from the source phase to the receiving phase by the carrier of the organic phase. Several factors involved in the transport of metal ions acrose the emulsion membrane we reported here and these factors provided the informations for the selective seperation of some metal ion. Stability constants for cation-macrocyclic ligand and metal ion-anion receiving phase interaction are examined as parameters for the prediction of metal ion transport selectivities. $Pb^{2+}$ was transported higher rates than the other metal ions in the mixture solution. The interaction of metal ion to anion in receiving phase is important. $S_2O_3^{2-}$- in replacement of $NO_3^-$ in the receiving phase enhances the transport of $Pb^{2-}$since $Pb^{2-}-S_2O_3^{2-}$interaction is greater than $Pb^{2+}-NO_3^-$ interaction.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.129-135
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• 1994

Acyclic polyether dicarboxylic acid have been studied as metal cation carriers in a bulk liquid membrane system. The proton-ionizable ligands feature allows the coupling of a cation transport to reverse proton transport. This feature offers promise for the effective separation and concentration of metal cations with the metal cation transport being driven by a pH gradient. Metal cation transport increased regularly with increasing hydroxide($H^-$) concentration of source phase and with proton($H^+$) concentration of receiving phase. Competitive transport by the acyclic polyether dicarboxylic acids is selective for calcium ion over other alkaline-earth cations.

• KSBB Journal
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• v.8 no.4
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• pp.370-374
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• 1993

In transportation the amount of metal ion by crown ethers, dibenzo-18-crown-6 were investigated using ultraviolet spectrometer. Transported the amount of one valence metal ion as $K^+ and Li^+}$ was not so much. On the other hand, two valence metal ion increased by dibenzo-18-crown-6, which means that the ionic charge and hydration of two valence metal ion affected the carrying ability of crown ethers. The carrying ability of dibenzo-18-crown-6 was, therefore, adequate for two valence metal ion as $Ca^{2+}$ and $Ba^{2+}$. It was also suggested that transport metal ion by crown ethers, which is related rather the catching ability than the selectivity of metalion.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.545-545
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• 2012

집속이온빔장치(FIB: Focused Ion Beam System)에 사용하는 액체금속이온원(LMIS: Liquid Metal Ion Source)은 고 전류밀도, 고 휘도, 낮은 에너지퍼짐 등 많은 장점이 있다. 집속이온빔장치는 주로 표면 분석, 집적 회로의 수정, 마스크 교정(Repair) 및 잘못된 부분의 분석(Failure Analysis) 등에 사용되고 있는데 최근에는 고 분해능의 이온빔 리소그래피와 이온 주입의 기술 및 미세가공 기술 등의 분야에 집중되고 있으며 이를 위해서는 집속이온빔장치의 수렴성(Convergence)을 개선해 나가는 것이 중요하다. 집속이온빔장치의 수렴성은 이온빔의 에너지 퍼짐(Energy Spread)과 각 분포(Angular Distribution)에 많은 영향을 받으며 에너지퍼짐 특성은 색수차에 직접적인 영향을 준다. 수렴성을 개선하기 위해 기존의 에미터(Emitter), 저장소(Reservoir), 추출극(Extractor)으로 제작된 액체금속이온원에 서프레서(Suppressor)라는 새로운 전극을 사용하여 이 전극의 유 무에 따른 각 분포의 변화에 대해 연구하였다.

• Analytical Science and Technology
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• v.8 no.3
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• pp.259-264
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• 1995

The separation efficiency of metal ions by using the poly-NTOE(1, 12-diaza-3, 4:9, 10-dibenzo-5, 8-dioxacyclopentadeca-1, 12-ylene-2, 7-dihydroxyoctamethylene) has been determined by column chromatography in aqueous solution. Binding constants and separation factors for several poly-NTOE interactions were measured in aqueous solution. The order of these binding constants and separation factors with metal ions were Co(II)Zn(II) for the transition metal ions and Cd(II)

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.360-363
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• 2005

본 연구에서는 인듐 액체금속이온원을 제작하여 빔 특성에 대해 연구를 하였으며, 기존의 연구를 하였던 갈륨 액체금속 이온원의 빔특성과 비교분석 하였다. 빔특성 분석을 위해 빔 안정도, 전류-전압특성곡선, 에너지 퍼짐을 측정하였다. 액체금속이온원에 사용되는 액체금속 저장소 및 바늘전극(tip)은 $500{\mu}m$의 직경을 갖는 텅스텐을 사용하였으며, 국내에서 제작된 제품을 사용하였다. 액체금속 저장소의 구조는 이전에 구상하여 연구가 이루어진 6개의 pre-etching된 텅스텐와이어(wire)가 묶여진 형태를 사용하였다.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.341-347
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• 1985

Formation of metal complex is the first step in the many biological actions of metal ions present in the biological systems. In this work the not electron affinity necessary for the formation of such metal complexes has been determined for a series of metal ions. It has been found that excess polarizing strength can be adopted as a measure of electron affinity and trend is the excess polarizing strength is related to Irving-Williams series. Those metal ions having greater than 0.22 in value of excess polarizing strength have been found to show carcinogenicity and other metal ions, which are supposed to be carcinogenic, have shows to have greater than 0. 22 in value of excess polarizing strength, demonstrating that excess polarizing strength could be used to determine if any metal ion possesses carcinogenic activity.