• Environmental Engineering Research
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• v.7 no.4
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• pp.227-237
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• 2002

Chemical vapor deposition (CVD), ion beam sputtering (IBS) and sol-gel method were used to prepare TiO$_2$ thin films for degradation of hazardous organic compounds exemplified by 2-chlorophenol (2-CP). The influence of supporting materials and coating methods on the photocatalytic activity of the TiO$_2$ thin films were also studied. TiO$_2$ thin films were coated onto various supporting materials including steel cloth (SS), copper cloth, quartz glass tube (QGT), and silica gel (SG). Results indicate that SS (37 μm)- TiO$_2$ thin film prepared by IBS method improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 μm) is found to be the best support.

• BMB Reports
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• v.35 no.2
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• pp.165-171
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• 2002

A serine collagenolytic protease was purified from the internal organs of filefish Novoden modestrus, by ammonium sulfate, ion-exchange chromatography on a DEAE-Sephadex A-50, ion-exchange rechromatography on a DEAE-Sephadex A-50, and gel filtration on a Sephadex G-150 column. The molecular mass of the filefish serine collagenase was estimated to be 27.0 kDa by gel filtration and SDS-PAGE. The purified collagenase was optimally active at pH 7.0-8.0 and $55^{\circ}C$. The purified enzyme was rich in Ala, Ser, Leu, and Ile, but poor in Trp, Pro, Tyr, and Met. In addition, the purified collagenolytic enzyme was strongly inhibited by N-P-toluenesulfonyl-L-lysine chloromethyl ketone (TLCK), diisopropylfluorophosphate (DFP), and soybean trypsin inhibitor.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.241-247
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• 1985

The objectives of this study were to isolate and identify ninhydrin positive substande(s) produced in the culture broth of Pseudomonas fluorescens. It was found that the NPS could stimulate bioconversion of furfural into furoic acid. In order to isolate the NPS from the culture broth, cell free filtrate was subjected to ion-exchange chromatography, gel-permeation and finally to cellulose column chromatography. The purified NPS was white amorphous power and very soluble in water, slightly soluble in methanol and very insoluble in organic solvents. UV, and IR absorption spectra. $^H$ and $^{13}C-NMR$ were measured in order to identify the chemical structure of the NPS.

• Journal of Life Science
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• v.11 no.6
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• pp.561-567
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• 2001

To isolate and purify fibrinolytic active substance from Sarcodon aspratus(N $H_4$)$_2$S $O_4$ precipitation, DE52 anion exchange column chromatography, Sephacryl-S 200gel filtration chromatography and Mono S cation FPLC were carried out and the characterizations of the purified enzyme were investigated. The bound active fraction on DE52 anion exchange column chromatography were eluted with 0.2 M NaCI and the fibrionlytic enzyme was purified after following Sephacryl-S200 gel fitration chromatography and Mono S cation EPLC. The specific activity of purified enzyme was 55.2 U/mg protein and increased 11.3 fold comparing crude extract and the yield was 49.5%. 12% SDS-PAGE electrophoresis and gel filtration chromatography revealed that Sarcodon aspratus fibrionloytic enzyme was highly purified and had 29.300 Da molecular weight. Enzyme activity of the purified fibrinolytic enzyme from Sarcodon aspratus was increased on higher pH and was stable until pH 10.5. On temperature dependent stability, the enzyme activity was decrease sharply but remained 25% relative activity on 8$0^{\circ}C$. This enzyme activity was inhibited by heavy metal ion, C $U^{2+}$ and $Co^{3+}$ with 68% and 38%, respectively. And also, the enzyme activity was inhibited with $Ca^{2+}$ chelator EDTA and serine protease inhibitor PMSF. These results from this study suggested that the fibrinolycit enzyme from Sarcodon aspratus is a serine protease and the enzyme activity was increased by $Ca^{2+}$ or $Mg^{2+}$ ion.n.ion.n.

• Solar Energy
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• v.12 no.2
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• pp.18-27
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• 1992

Multilayer coatings of $WO_3$ were deposited by the sol-gel technique on microscope slide glass and ITO coated glass. These films were characterized optically, chemically, and structurally by XRD, spectro-photometry, DTA/TGA, SEM/EDAX and RBS. Uniform $WO_3$ sol-gel films were dip coated on slide glass at dipping speed of 5mm/s. This sample indicated a low near IR transmittance in optical properties as a result of coloration using a dilute HCI electrolyte as the $H^+$ion sources. Differential thermal analysis results have allowed the accurate determination of the formation temperature of the $WO_3$ crystalline phase from the gel data in the range of $380^{\circ}C{\sim}500^{\circ}C$, consistent with crystallization temperature of sol-gel film. RBS spectrometry was performed on the uncolored $WO_3$ sol-gel film, yielding a chemical composition of $WO_3$.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.371-380
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• 1989

The purpose of this experiment is to elucidate the reaction mechanism concerning to the formation of crystalline BaTiO3 synthesized by adding the pH control agent(KOH soln) in TiCl4 and BaCl2 solution (Wet direct synthetic method). In this expeirment, it is identified that the amorphous barium-titanate having Ba-O-Ti bonding is formed above pH5 due to the -OH- ion and Ti-gel is formed below pH5 due to the polymerization of metatitanic acid. The bonding of the amorphous Ba-O-Ti is identified by FT-IR spectrum and crystallization temperature is about 82$0^{\circ}C$. If the pH of the above system according to the -OH- ion concentration is above 13.8, the polymerized metatitanic acid will be depolymerized and produce [TiO3]2+ion and crystalline BaTiO3 is formed by reacting the produced [TiO3]-- ion with the active Ba++ ion.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.608-612
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• 2012

We investigated the cycling behavior of $Li_4Ti_5O_{12}$ electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The $Li_4Ti_5O_{12}$ electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %.

• Journal of the Korean Electrochemical Society
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• v.5 no.4
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• pp.197-201
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• 2002

In this study, a gel polymer electrolyte was prepared from urethane acrylate and its electrochemical performances were evaluated. And, $LiCoO_2/GPE/graphite$ cells were prepared and their performances depending on discharge currents and temperatures were evaluated. The precursor containing $5 vol\%$ curable mixture had a low viscosity relatively. Ionic conductivity of the gel polymer electrolyte at room temperature and $-20^{\circ}C$ was ca. $5.9\times10^{-3}S{\cdot}cm^{-1}\;and\;1.7\times10^{-3}S{\cdot}cm^{-1}$, respectively. GPE showed electrochemical stability up to potential of 4.5V vs. $Li/Li^+.LiCoO_2/GPE/graphite$ cell showed a good high-rate and a low-temperature performance.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.523-523
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.524-532
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.