• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.219-222
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• 2001

Membranes which selectively transport specific metals on an industrial scale is much useful in a number of applications, such as aqueous stream purification, catalyst and recycling of the reactants, the applications in metal ion sensing and so forth. Numerous studies have been already made to use liquid, supported liquid and, emulsion liquid membranes (LM) for selective carriers for metal ion transport. (omitted)

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.735-742
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• 2019

In this work, the electrokinetic interactions between the undulated structure of an ion-selective membrane and electroconvective instability has been studied using numerical analysis. Using finite element method, electric field-ionic species transport-flow field were analyzed by fully-coupled manner. Through the numerical study, the Dukhin's mode as the mechanism of undulated surface for the electroconvective instability were proven. The Dukhin's mode which competes with Rubinstein's mode has roles of (i) decreasing transition voltage to overlimiting regime and (ii) non-linearly increasing of overlimiting current. Also, (iii) the mixing efficiency is enhanced by removal mechanism of high-frequency Fourier mode of the electroconvective instability. Conclusively, the undulated ion-selective surface would provide energy-efficient mechanism for ion-selective transport systems such as electrodialysis, electrochemical battery, etc.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.930-934
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• 2005

A chloroform membrane system containing a given mixture of benzylaza-12-crown-4 and oleic acid is introduced for the selective and efficient transport of $Pb^{2+}$ ion. The transport was capable of moving metal ions ‘up-hill’. In the presence of ${S_2O_3}^{2-}$ion as a suitable metal ion acceptor in the receiving phase, the amount of lead ion transport across the liquid membrane after 150 minutes is (95.0 ${\pm}$ 1.7)%. The selectivity and efficiency of lead transport from aqueous solution containing $Tl^+,\;Ag^+,\;Mg^{2+},\;Ca^{2+},\;Co^{2+},$ $Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Hg^{2+}$ and $Cd^{2+}$were investigated. In the presence of thiosulfate as a suitable masking agent in the source phase, the interfering effects of $Ag^+\;and\;Cu^{2+}$ were diminished drastically.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.416-422
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• 1993

In order to prepare high performance polymeric membrane, the crosslinked chitosan(C. Chitosan)membrane was prepared, the transport and the selective separation of the metal ions through the membrane were investigated. It was observed that the transport rates of the metal ions through the membrane increased according to the decreasing of the initial pH in downstream solution. Proton pump mechanism for this transport phenomenon was suggested. The transport selectivity is dependent on the selective adsorption resulting from the complex formation of chitosan with each metal ion. The separatin factor(${\alpha}_{Cu}{^{2+}}$) for the membrane was 9.5.

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1256-1260
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• 1997

A series of acyclic polyethers bearing amide end-groups and lipophilic alkyl chains (3-5) were successfully synthesized with quantitative yields. Based upon the transport experiment in a bulk liquid membrane (BLM) system and solvent extraction, a very high selectivity of Pb2+ over other transition metal cations was observed. Measurement of thermodynamic parameters for complexation in methanol at 25 ℃ gave a strong evidence for excellent selective complexation for lead ion over other transition metal ions.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.85-91
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• 2013

The selective transport characteristics of $K^+$ and $Na^+$ of cell membrane model which irradiated by 60Co ${\gamma}$-ray was investigated. The cell membrane model used in this experiment was a Na+ type sulfonated copolymerized membrane of styrene and divinylbenezene. The initial flux of the ion was increased with increase of both $H^+$ ion concentration. In this experiment range(pH 0.5-3, temperature $15-65^{\circ}C$), first, the selectivity of $K^+$ and the ratio K+/Na+ of membrane which was not irradiated was about 1.06 - 1.13 and second, that of K+ and the ratio $K^+/Na^+$ of membrane which was irradiated was near about 0. And the driving force of pH of irradiated membrane was significantly increased about 4-5 times than membrane which was not irradiated. As selective transport of K+ and Na+ of cell membrane model were abnormal, cell damages were appeared at cell.

• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.699-702
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• 2001

A series of cleft-type ionophores having two convergent hydroxamic acid functions are prepared and their selective ionophoric properties toward heavy metal and transition metal ions have been investigated. Hydroxamic acids 3 exhibited a prominent selectivity toward heavy metal ions of Hg2+ and Pb2+, and transition metal ions of Cu2+ over other transition metal and alkaline earth metal ions from slightly acidic source phase (pH 6) to an acidic receiving phase (pH 1). Selective ionophoric properties toward Pb2+ and Cu2+ ions over other surveyed metal ions are also confirmed by the FAB-MS measurements.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.319-324
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• 2020

Electroconvective instability is a non-linear transport phenomenon which can be found in ion-selective transport system such as electrodialysis, Galvanic cell and electrolytic cell. The instability is triggered by the fluctuation of space charge layer in adjacent of ion-selective surface, leading to increase of mass transport rate. Thus, in the aspect of mass transport, the instability has an important meaning. Although recent experimental techniques have opened up an avenue to direct visualize the instability, fundamental investigations have been conducted in limited area due to several experimental limitations. In this work, the electroconvective instability under potentiostatic mode was solved by numerical method in order to demonstrate correlation between current-time curve and the instability behavior. By rigorous time-resolved analysis, the transition behaviors can be divided into three stages; formation of space charge layer - growth of electroconvective instability - steady state. Furthermore, scaling laws of transition time were numerically obtained according to applied voltage as well.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.489-493
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• 2003

2-Mercaptobenzothiazole was used as a highly selective and efficient carrier for the uphill transport of silver ion through a chloroform bulk liquid membrane. In the presence of thiosulfate ion as a suitable metal ion acceptor in the receiving phase, the amount of silver transported across the liquid membrane after 180 min was 90 ± 3.0%. The selectivity and efficiency of silver ion transported from aqueous solutions containing equimolar mixtures of $Zn^{2+}, Cu^{2+}, Co^{2+}, Ni^{2+}, Cd^{2+}, Pb^{2+}, Bi^{3+}, Fe^{2+}, Fe^{3+}, Pd^{2+}, Mn^{2+}, Hg^{2+}, Sn^{2+}, Ca^{2+}, Mg^{2+}, K^+, Na^+ and Li^+$ were investigated.

• Fibers and Polymers
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• v.3 no.1
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• pp.14-17
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• 2002

Development of a novel fixed site carrier membrane (FCM), supported by PET fabric for metal ion separation is reported. The membranes were prepared by dipping PET fabric into the methylene chloride solution of Poly(5-vinyl-m-phe-nylene-m'-phenylene-32-crown-10) (P(VCE)), a polymeric metal ion carrier. It was found that the flux of mono-valent metal ion transported across the membrane is signif=cantly differed from each other and the flux decreases in the order $Cs^+$>$Rb^+$>$K^+$>$Na^+$>$Li^+$ irrespective to the anion except perchlorate anion. It was explained in terms of the stability of the complex, formed by crown ether unit of the P(VCE) and the various metal ions, meanwhile, the lower rate of transport in the presence of perchlorate anion was ascribed to its low hydrophilicity.