• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.5
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• pp.384-390
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• 2006

To improve the extractability of carnosine and the levels of pro-oxidants such as iron in eel (Anguilla japonica) extracts, we examined the effects of extraction time, temperature, ion exchange chromatography and ultrafiltration (UF). The respective protein and total iron were reduced approximately 55 and 60% at 60$^{\circ}C$, 63 and 70% at 80$^{\circ}C$, 68 and 76% at 100$^{\circ}C$ and 82 and 48% with ion exchange chromatography, respectively, compared to the untreated extract. However, there was no significant difference in the carnosine levels in the eel extracts. Ultrafiltration reduced the protein content of the extract by 52% compared with the untreated extract. UF reduced the protein contents of the samples from 60, 80, and 100% heat treatment and ion exchange chromatography treatment by 27, 50, 46 and 47%, respectively. UF reduced the total iron contents of the identical four treatments by 14, 22, 23, and 43%, respectively, while UF increased the carnosine by 23, 17, 20, and 6%, respectively.

• Membrane Journal
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• v.12 no.3
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• pp.143-150
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• 2002

Electrodialysis(ED) is a reliable and effective process for the separation and concentration of ionic compounds. However, commercial uses of ED are often hindered by the cost of the stack that mainly resulted from the ion-exchange membrane cost. In order to minimize the membrane cost, it is desired to operate ED at the highest practicable current density. In an actual ED system the high current operation is limited by the concentration polarization phenomenon. This article illustrates the transport phenomena of ions through ion exchange membranes using current-voltage relations as a characterizing method. Also recent studies on electroconvection and water-spitting phenomena caused by concentration polarization were reviewed.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.1-4
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• 2003

LDPE/polystyrene cation exchange membranes were prepared through a monomer-sorption method and UV radiation polymerization. The reaction behaviors in the preparation were investigated. The membranes prepared were characterized in terms of physical and electrochemical properties. The membranes exhibited reasonable properties for an ion-exchange membrane with weight gain (Wr) of above 0.3, electrical resistance of below 1.0 Ω $\textrm{cm}^2$ and ion-exchange capacity of 1.8 meq/g-dry membrane. DSC studies and FE-SEM image revealed the formation of a homogeneous membrane. Both the current-voltage and the chronopotentiometric curves of the membranes indicated that LDPE/polystyrene membranes can be properly used at a high current density, and the surface homogeneity of cation-exchange sites in the membrane was comparable to that in a commercial membrane.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.63-68
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• 1986

Elution behavior of rare earth elements have been investigated with the EDTA solution as an eluent using cation exchange resin. Definite amount of the complexed rare earth ions at pH 8.4 is adsorbed through the cation exchanger containing cupric ion as a retaining ion and eluted with EDTA solution. The rare earth ions are eluted more rapidly in the above method than in the method in which uncomplexed rare earth ions are adsorbed on the cation exchange resin bed. In this method, the elution time and amount of eluent are saved but the resolution values also decreased a little. The elution order of complexed ion was determined in accordance with the stability constant of complexes with rare earth elements.

• Journal of Pharmaceutical Investigation
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• v.21 no.2
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• pp.111-116
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• 1991

Dextromethorphan HBr (DMP HBr) ion exchange albumin microcapsules were prepared by the interfacial polymerization method. The incorporation of drugs in empty albumin microcapsules was more increased in case of glutaraldehyde (GA) and formaldehyde (FA) than terephthaloyl chloride (TC) as a cross linking agent. The amount of DMP HBr incorporated into empty albumin micorcapsules was augemented with increasing DMP HBr concentration and the amount of empty microcapsules in the incorporation medium. Increasing the salt concentration in the release medium, the release rate and the DMP HBr amount released from microcapsules were increased. The release rates of DMP HBr from microcapsules retarded considerably compared with DMP HBr powder.

• Membrane Journal
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• v.32 no.4
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• pp.209-217
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• 2022

Ion exchange membrane (IEM) is an important class of membrane applied in batteries, fuel cells, chloride-alkali processes, etc to separate various mono and multivalent ions. The membrane process is based on the electrically driven force, green separation method, which is an emerging area in desalination of seawater and water treatment. Electrodialysis (ED) is a technique in which cations and anions move selectively along the IEM. Anion exchange membrane (AEM) is one of the important components of the ED process which is critical to enhancing the process efficiency. The introduction of cross-linking in the IEM improves the ion-selective separation performance due to the reduction of free volume. During the desalination of seawater by reverse osmosis (RO) process, there is a lot of dissolved salt present in the concentrate of RO. So, the ED process consisting of a monovalent cation-selective membrane reduces fouling and improves membrane flux. This review is divided into three sections such as electrodialysis (ED), anion exchange membrane (AEM), and cation exchange membrane (CEM).

• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1324-1328
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• 2003

The simultaneous determination of anions ($SO_4 ^{2-},\;Cl^-,\;and\;NO_3^-$) and cations ($Na^+,\;NH^{4+},\;K^+,\;Mg^{2+},\;and\;Ca^{2+}$) in natural water obtained by Nakdong River waters system in Korea were performed by ion-exclusion/cationexchange chromatography with conductimetric detection. The stationary phase was a polymethacrylate-based weakly acidic cation-exchange resin column in the $H^+$-form and a weak-acid eluent. When using only a 1.4 mM sulfosalicylic acid/6 mM 18-crown-6 ether as an eluent, good resolution of both anions and cations, minimum time required for the separation, and satisfactory detection sensitivity were obtained in a reasonable time. The method was successfully applied to the simultaneous determination of anions and cations in natural waters.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.286-286
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• 2013

수산화인회석(Hydroxyapatite)는 뼈와 이빨의 무기물의 주성분으로서 칼슘과 인산염으로 구성된다. 수산화인회석의 합성방법은 수열합성법(hydrothermal method)를 사용하였으며 NaOH 농도조절을 통해 다양한 수산화인회석을 합성하였다. 합성된 수산화인회석을 XRD로 확인하였으며 Hydroxyapatite 표면에 Cobalt를 Ion-exchange 반응을 통하여 도입하였으며, 이를 다시 hydrazine을 매개체로 하여 Fe (Iron)를 도입하였다. 합성된 수산화인회석을 IR로 분석하였고, ICP를 통해 Co, Fe를 정량하였으며 TEM을 통해 표면을 관찰하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.209.1-209.1
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• 2014

수산화인회석(Hydroxyapatite)는 뼈와 이빨의 무기물의 주성분으로서 칼슘과 인산염으로 구성된다. 본 실험에서는 다양한 농도의 염기조건(NaOH 0,2,4,5,10 M)하에서 서로 다른 형태의 수산화인회석을 수열합성법(hydrothermal method)을 이용해 합성하였다. 합성된 각각의 수산화인회석을 XRD로 확인하였고 일정 농도 이하에서는 octacalcium phosphate이 함께 존재한다는 것을 확인하였다. 수산화인회석 표면에 Ru를 Ion-exchange 반응을 통하여 도입하였으며, 도입된 표면을 TEM을 확인하였다. Ru를 도입한 수산화인회석을 benzyl alcohol과 benzyl amine을 산화반응에 응용하였다.

• Journal of the Korean Ceramic Society
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• v.20 no.3
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• pp.205-210
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• 1983

The determination of charge density and charge distribution in montmorillonite are discussed. The method is based on cation exchange of the inorganic interlayer cations against decylammonium ion and molecular intercalation of n-alcanol. The results obtained from Yougil-bentonite show that charge density of 0.37 per unit formula and cation exchange capacity of 102.5 meq/100g.