• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.373-374
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• 2005

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.837-840
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• 2005

• Membrane Journal
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• v.2 no.1
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• pp.49-58
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• 1992

Functionalized organic polymers have been used as supports for heterogenized homogeneous catalytic process[1]. Sprcific advantages of using these resins as support reagents have been reviewed[2-4]. These include: -ease of by-product separation from the main reaction product usuallyby simple filtration. -prevention of intermolecular reaction of reactive species or functional groups by simulating high dilution conditions[5]. -utility of the "fish-hook" principle in which a minor component in fished out of a large excess substrate by the insoluble polymer[6]. -the possibility of reusing recovered reagents as well as eliminating the use of volatile or noxious substances[7]. Catalysis by ion-exchange membranes is perhaps one of the latest examples of the use of a polymer-supported species. Conceptually, catalysts on membrane supports offer several possible advantages over traditional powder type systems. They are: (1) Membranes immobilize the catalyst, preventing agglomeration. (2) Filtration is unnecessary for the catalyst separation and so complete catalyst recovery is facilitated. (3) Catalytyic and separation processes can be combined, allowing membrane supported catalysts for the continous flow reactors. reactors.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.563-566
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• 2002

Copper complexes have been directly incorporated into cellulose acetate (CA) and the resulting light blue colored homogeneous films of 5-20 wt.% copper acetate complex concentrations are found to be thermally stable up to 200 $^{\circ}C$. The reaction chem istry of Cu in CA has been investigated by reacting them with small gas molecules such as CO, H2, D2, O2, NO, and olefins in the temperature range of 25-160 $^{\circ}C$, and various Cu-hydride, -carbonyl, -nitrosyl, and olefin species coordinated to Cu sites in CA are characterized by IR and UV/Vis spectroscopic study. The reduction of Cu(II) complexes by reacting with H2 gas at the described conditions results in the formation of Cu2O and copper metal nanoparticles in CA, and their sizes in 30-120 nm range are found to be controlled by adjusting metal complex concentration in CA and/or the reduction reaction conditions. These small copper metal particles show various catalytic reactivity in hydrogenation of olefins and CH3CN; CO oxidation; and NO reduction reactions under relatively mild conditions.

• Macromolecular Research
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• v.16 no.5
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• pp.429-433
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• 2008

Alginate/carboxymethyl scleroglucan (CMSG) hydrogels were suggested as a novel carrier for the controlled release of protein drugs. The drug release characteristics of alginate hydrogels were improved by CMSG addition. Scleroglucan (Sclg) was carboxymethylated using monochloroacetic acid in aqueous alkaline medium. Alginate/CMSG hydrogels were prepared by dropping the mixture solution of alginate/CMSG into calcium chloride solution. The swelling behaviors and drug release characteristics of the hydrogels were investigated in the buffers of pH 1.2 or 7.4. As the CMSG content increased in the hydrogels, the swelling ratio of the alginate/CMSG hydrogel increased rapidly in the buffer of pH 7.4. At pH 1.2, however, the swelling ratio significantly decreased compared to that at pH 7.4. According to in vitro release tests, only 15% of ovalbumin, investigated as a model protein drug, was released from the alginate/CMSG hydrogels at pH 1.2 within 6 h. At pH 7.4, however, the drug release significantly increased due to the rapid swelling of the hydrogels. The release and swelling behaviors of the hydrogels could be controlled by changing the CMSG content in the hydrogels. These results supported the use of alginate/CMSG hydrogels as a suitable carrier for the controlled release of protein drugs in a pH responsive manner.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.443-455
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• 2013

Electrochemical studies on charge transfer reactions across the interface between two immiscible electrolyte solutions (ITIES) have greatly attracted researcher's attentions due to their wide applicability in research fields such as ion sensing and biosensing, modeling of biomembranes, pharmacokinetics, phase-transfer catalysis, fuel generation and solar energy conversion. In particular, there have been extensive efforts made on developing sensing platforms for ionic species and biomolecules via gelifying one of the liquid phases to improve mechanical stability in addition to creating microscale interfaces to reduce ohmic loss. In this review, we will mainly discuss on the basic principles, applications and future aspects of various sensing platforms utilizing ion transfer reactions across the ITIES. The ITIES is classified into four types : (i) a conventional liquid/liquid interface, (ii) a micropipette supported liquid/liquid interface, (iii) a single microhole or an array of microholes supported liquid/ liquid interface on a thin polymer film, and (iv) a microhole array liquid/liquid interface on a silicon membrane. Research efforts on developing ion selective sensors for water pollutants as well as biomolecule sensors will be highlighted based on the use of direct and assisted ion transfer reactions across these different ITIES configurations.