• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.578-581
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• 1991

The antioxidative effects of three kinds of commercial lecithin in fish oil(EPA 25%, DHA 10%) were investigated through active oxygen method (AOM, hrs. at $97.8^{\circ}C$), Oven test, polymer test by gel chromatography and coloring test. Although there were difference of antioxidative effect among commercial lecithins, antioxidative effects of the lecithins added to the fish oil increased with increasing the concentration of lecithin. Lecithin III(acetone insoluble content 65%) had the greatest antioxidative effect and the addition of 1%, 5 and 10% enhanced the oxidative stability to 310%, 620% and 840%, respectively. The results also showed that the polymerization in presence of 10% lecithin III did not occur up to 10 hours at the AOM condition, and the degree of color(Gardner number) increased as storage time went by and was accerated at high temperature.

• KSBB Journal
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• v.23 no.4
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• pp.340-344
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• 2008

Coprinus cinereus peroxidase (CiP) was often used as a catalyst for oxidative polymerization of a variety of phenol derivatives to produce a new class of polyphenols. Economical point of view, to know the mechanism of enzyme deactivation is significantly important because cost of enzyme is critically high. Hydrogen peroxide being used as oxidizing agent induced deactivation of peroxidase by destruction of heme structure. In the presence of hydrogen peroxide the stability of peroxidase was unexpectedly improved by adding organic solvent. Especially 2-propanol significantly improved enzyme stability among tested solvents. Radical scavenging by organic solvents may play a major role in protecting peroxidase from the oxidation of oxidizing radicals.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.484-488
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• 2003

Polycarbosilanes containing diacetylene and organosilacyclic groups, such as poly(1,1-diethynyl-1-silacyclopent-3-ene), poly(1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene), and poly(1,1-diethynyl-1- silacyclobutane), were synthesized by the Glaser oxidative coupling polymerization reactions of 1,1-diethynyl-1-silacyclopent-3-ene, 1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene, and 1,1-diethynyl-1-silacyclobutane, respectively. These materials are almost insoluble in usual organic solvents such as $CHCl_3$ and THF. The polymers were characterized by using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic C≡C stretching frequencies appear at 2146-2170 $cm^{-1}$, in particular. The polymers in the solid state show that the strong maximum excitation peaks appear at 255-257 nm and the strong maximum fluorescence emission bands at 401-402 nm. About 71-87% of the initial polymer weights remain at 400 ℃ in nitrogen according to thermogravimetric analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05a
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• pp.6-10
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• 2001

We synthesized polypyrrole (PPy) nanotubules by oxidative polymerization of the pyrrole monomer on the pore of a polycarbonate membrane. The electrochemical behavior was investigated using cyclic voltammetry and AC impedance. The redox potential was about -0.5 V vs. Ag/AgCl reference electrode, while the potential was about 0 V for electro-synthesized PPy film. It is considered as the backbone grows according to the pore wall. Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. The AC impedance plot gave a hint of betterment of mass transport. PPy nanotubules have improved in mass transport, or diffusion. That is because the diffusion occurs through a thin pore wall of PPy nanotubules. The kinetic parameter of PPy nanotubules enzyme electrode with glucose solution was evaluated. The formal Michaelis constant and maximum current calculated by computer were about 23.8 mmol $dm^{-3}$ and $440\;{\mu}A$ respectively. Obviously, an affinity for the substrate and current response of the PPy nanotubules enzyme electrode are rather good, comparing with that of PPy film. What is more, the enzyme electrode is sensitive to blood sugar of a diabetic serum despite an obstruction of ascorbic acid, oxygen, some protein and/or hormone.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1305-1310
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• 2007

A conjugated spirocyclic polymer was synthesized via the cyclopolymerization of 1,1-dipropargyl-1- silacyclohexane with various transition metal catalysts. The monomer, 1,1-dipropargyl-1-silacyclohexane was synthesized by Grignard reaction of 1,1-dichloro-1-silacyclohexane with propargyl magnesium bromide. This polymerization proceeded well to give the corresponding poly(1,1-dipropargyl-1-silacyclohexane). The catalytic activity of WCl6 was found to be similar with that of MoCl5. The structure of polymer having the conjugated backbone with silacyclohexane moieties was characterized by such instrumental methods as NMR (1H-, 13C-), IR, and UV-visible spectroscopies. The resulting polymers were mostly yellow or light-brown powders, depending on the catalyst systems used. This polymer was completely soluble in halogenated and aromatic hydrocarbons such as chloroform, 1,2-dichloromethane, benzene, toluene, and chlorobenzene, etc. The thermal and oxidative stabilities of polymer were also studied and discussed.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.927-933
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• 2011

Conducting polyaniline-poly($\varepsilon$-caprolactone) polymer composites were synthesized via in situ deposition techniques. By dissolving different weight percentages of poly($\varepsilon$-caprolactone) (PCL) (10%, 20%, 30%, 40%, and 50%), the oxidative polymerization of aniline was achieved using ammonium persulfate as an oxidant. FTIR, UV-vis spectra, and X-ray diffraction studies support a strong interaction between polyaniline (PANI) and PCL. Structural morphology of the PANI-PCL polymer composites was studied using scanned electron microscopy (SEM) and transmittance electron microscopy (TEM), and thermal stability was analyzed by thermogravimetric analysis (TGA) technique. The temperature-dependent DC conductivity of PANI-PCL polymer composite films was studied in the range of 305-475 K, which revealed a semiconducting behavior in the transport properties of the polymer films. Conductivity increased with the increase of PCL in below critical level, however conductivity of the polymer film was decreased with increase of PCL concentration higher than the critical value.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.454-458
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• 2009

Polypyrrole (PPy) nanotubes have been synthesized by chemical oxidative polymerization of pyrrole within the pores of polycarbonate membrane using the technology of diffusion of solutes. The nanotubes array prepared by the proposed method can be considered as nanoelectrode ensembles (NEEs). An amperometric uric acid sensor based on PPy NEEs has been developed and used for determination of uric acid in human serum samples. The electrode can direct response to uric acid at potential of 0.60V vs. SCE with wide linear range of $1.52{\times}10^{-6}\;to\;1.54{\times}10^{-3}\;M.\;The\;detection\;limit\;is \;3.02{\times}10^{-7}$ M. This sensor has been used to determine uric acid in real serum samples. PPy NEEs is thought of as a good application in the foreground.

• Macromolecular Research
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• v.16 no.3
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• pp.200-203
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• 2008

A conducting polymer layer was introduced into the pore surface of mesoporous carbon via vapor infiltration of a monomer and subsequent chemical oxidative polymerization. The polypyrrole, conducting polymer has attracted considerable attention due to the high electrical conductivity and stability under ambient conditions. The mesoporous carbon-polypyrrole nanocomposite exhibited the retained porous structure, such as mesoporous carbon with a three-dimensionally connected pore system after intercalation of the polypyrrole layer. In addition, the controllable addition of pyrrole monomer can provide the mesoporous carbon-polypyrrole nanocomposites with a tunable amount of polypyrrole and texture property. The polypyrrole layer improved the electrode performance in the electrochemical double layer capacitor. This improved electrochemical performance was attributed to the high surface area, open pore system with three-dimensionally interconnected mesopores, and reversible redox behavior of the conducting polypyrrole. Furthermore, the correlation between the amount of polypyrrole and capacitance was investigated to check the effect of the polypyrrole layer on the electrochemical performance.

• Analytical Science and Technology
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• v.19 no.3
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• pp.211-217
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• 2006

Diphenyl amine (DPA) was polymerized inside the channels of the mesoporous silica (MCM-41). MCM-41 (C) and MCM-41 (D) were prepared with cetyltrimethyl ammonium bromide (CTAB) and dodecyltrimethyl ammonium bromide (DTAB), respectively and used as hosts. Initially, the self assembly of DPA inside the pores of MCM-41 was made in ${\beta}$-naphthalene sulfonic acid (NSA) medium and subsequently poly (diphenylamine), PDPA was formed by oxidative polymerization. $N_2$ adsorption-desorption measurements of PDPA loaded MCM-41 (C) and MCM-41 (D) show variations in pore volume and surface area between them. A tubular form of poly (diphenylamine), PDPA was envisaged to form in the pores of MCM-41 and supported by high resolution transmission microscopy. The presence of PDPA inside the channel of MCM-41 was further confirmed by FTIR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.54-61
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• 2008

Purpose : This study was designed to clarify the mechanism of proteinuria in nephrotic syndrome patients by using puromycin aminonucleoside (PAN) nephrosis model. Methods : Following administration of various concentrations of PAN and antioxidants we observed the changes of podocyte cytoskeletons in cultured rat glomerular epithelial cells (GEpC) by method of scanning electron microscope, reactive oxyten species (ROS) analysis, permeability assay, confocal microscope, and Western blot assay. Results : PAN not only induced the ultrastructural changes of GEpC, such as shortening and fusion of microvilli, but also separated the intercellular gaps and linear ZO-1. PAN induced oxidative stresses in time and dose dependent manners and increases of intercellular permeability in anti-oxidants inhibitable manners. High concentration of PAN induced not only actin polymerization and disorganization, but also the conglomerulation and internal dislocation of ${\alpha}-actinin$ protein. The intensities of fluorescences of ZO-1 protein were diminished and internalized by PAN in a dose-dependent manner, which were inhibited by anti anti-oxidants. Conclusion : PAN induced the changes of podocytes cytoskeleton and junctional barriers by way of increasing ROS in GEpC that resulted in increasing their permeability in a antioxidatn-inhibitable manner. Glomerular hyperpermeability induced by PAN mediateing through oxidative stresses is thought to take part in the mechanism of proteinuria in nephrotic syndrome.