• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.393-401
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• 2012

Inorganic pigment is excellent at stability to human body and compatibility with different materials and has been used in a variety of field such as cosmetics, printing inks, paints, and construction materials for improving the aesthetic features. In this paper, hydrothermal synthesis method was used to prepare the manganese and iron dopped with titania pigment. As process parameters, the amount of manganese precursor and iron precursor, and calcined temperature was changed. Optimum amounts of manganese and iron dopped with titania precursor to give excellent color index was manganese 1.0wt% and iron 1.5wt% for dopped titania, and Optimum calcination temperature was $550^{\circ}C$. The synthesized pigments were analyzed by XRD, SEM, EDS, Spectrophotometer and UV-Vis Spectrometer.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.263-263
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• 2014

자외선 영역에서 우수한 광촉매 반도체인 이산화티탄($TiO_2$)은 환경, 에너지와 같은 분야 등에 유용하게 이용된다. 용액상에서 고활성 광촉매의 제조가 가능한 수열합성법에 의해 균일한 결정상의 나노 크기의 미세한 이산화티탄($TiO_2$) 입자를 제조하고, XRD, TEM, UV-vis-DRS, 그리고 염료의 광촉매 흡착 반응을 통하여 그 특성과 광촉매 효율을 조사하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.222-224
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• 2004

This study was performed to analyze the contents of titanium dioxide in commercial foods by UV/VIS spectrophotometry. This method incorporated foods reducing to ashes, dissolution of the ash in sulfuric acid and color development using hydrogen peroxide. The UV/VIS spectrophotometric response was compared to a standard solution. The contents of titanium dioxide in commercial foods were 1.56∼7.74 g/kg in chocolate, 0.27∼1.74 g/kg in health food, 0.48∼2.96 g/kg in chewing gum and 0.34∼2.34 g/kg in candy, respectively. Recoveries of titanium dioxide in foods were 88.46∼104.75％ accordingly.

• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.243-248
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• 2000

Oganic electroluminescent devices (OELD) with multilayer structures have been studied actively for the application to a flat-panel display. Netal-chelate complexes hrboxylate. These complexes were characterized by FT-IR, MS/FAB, $^1$H-NMR, UV-vis and photoluminescence (PL). More importantly, the electrochemical gap (Eg), electron affinity(EA) and ionization potential (IP) of these complex films were investigated. Data from cyclic voltammetry(CV) were compared with the bandgap obtained from UV-vis and discussed. Further studies on the EL of these new materials are now in progress.

• Journal of the Korean Chemical Society
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• v.61 no.4
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• pp.191-196
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• 2017

One-phase method to prevent the initial formation of Ag(I) thiolate layered materal from the mixture of $AgNO_3$ and thiols was previously developed to generate TP (Thiolate-Protected)-nanosilver. In this modified method, $AgNO_3$ is added to the mixtures of $NaBH_4$ and thiols in ethanol. This method was so successful that it was applied to synthesize TP-nanogold and nanoplatinum. The synthesis and characterization of these nanoparticles by ultraviolet-visible (UV-vis) absorption spectra, transmission electron microscopy (TEM) pictures, X-ray powder differaction (XRD) patterns and infrared(IR) spectra are described. The results show that colloidal nanoparticles are spherical or oval shape and the mean sizes for TP-nanogold and nanoplatinum are about 3~7 nm and below 2 nm, respectively. The conformation of polymethylene [$-(CH_2)_7-$] sequence in octanethiolate attached to nanogold was elucidated as trans.

• Journal of the Korean Vacuum Society
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• v.6 no.2
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• pp.114-121
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• 1997

The transparent conductiong thin films of tin oxides were prepared on pyrex glass substrates by the pulse laser deposition. In the atmospheres of vacuum, O2, and $Sn(CH_3)_4$ a polycrystalline $SnO_2$ target was ablated by Nd-YAG laser beam to deposit thin films on the substrates at room temperature, and as-deposited films were subsequently heat-treated in the air for 2 h at 230, 420 and $610^{\circ}C$, respectively. The characteristics of the thin films were examined by UV-VIS-NIR spectrometry and X-ray diffractometry, and the electrical properties were measured by four-point probe method along with film thickness monitored by the stylus method. It was observed that in the presence of $Sn(CH_3)_4$, $SnO_2$ phases were grown even at room temperature. This suggests that the microplasma producted during the laser ablation plays an important role in the dissociaation of precursor molecules.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.726-732
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• 2007

We fabricated UV absorption functional $10{\sim}50nm-TiO_{2-x}/quartz$ structures layer using ALD (atomic layer deposition) method. We deposited $10nm-TiO_{2-x}$ layer on quartz substrate using ALD, and film thickness was determined by an ellipsometer. The others specimen thickness was controlled by ALD time lineally. We characterized controlling phase UV and visible optical property using an X-ray difractometer, a UV-VIS-IR spectrometer and a digital camera. $ALD-TiO_{2-x}$ layers were non-stoichiometric $TiO_{2-x}$ form and amorphous phases comparing with bulk $TiO_2$. While the conventional bulk $TiO_2$ had band gap of $3.0{\sim}3.2eV$ resulting in absorption edges at 380 nm and 415 nm, $ALD-TiO_{2-x}$ layers showed absorption edges at 197 nm and 250 nm. Therefore, our nano-thick $ALD-TiO_{2-x}$ was able to absorb shorter UV region and showed excellent transmittance in visible region. Our result implies that our newly proposed nano-thick $TiO_{2-x}$ using ALD process may improve transmittance in visible rays and be able to absorb shorter UV light effectively.

• Elastomers and Composites
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• v.48 no.3
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• pp.209-215
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• 2013

On this study, visible-light responsive photocatalyst prepared by sol-gel method was evaluated the effect of the reduction of volatile organic compounds (VOCs) occurred in vehicle interior and its property was examined. According to UV/visible result, visible-light responsive photocatalyst was found that the UV-visible peak is red shift at 420nm, is sensitive in the visible light region. With vehicle interior parts and materials coated visible-light responsive photocatalyst, VOCs was measured by GC/MS. Measuring the VOCs generated from vehicle interior parts and materials, the reduction of VOCs was confirmed.

• Journal of the Korean Ceramic Society
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• v.34 no.9
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• pp.993-1001
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• 1997

The (0.8PPV+0.2DMPPV) copolymer and silica/borosilicate composites were synthesized by sol-gel process. The organic-inorganic hybrid solution was prepared by using of (0.8PPV+0.2DMPPV) copolymer precursor solution as a raw material for organic components and TEOS and TMB for glass components. Then by drying the solution in vacuum at 5$0^{\circ}C$ for 7days and subsequent heat treatment in vacuum at 15$0^{\circ}C$~30$0^{\circ}C$ for 2h~72h with heating rate of 0.2$^{\circ}C$/min and 1.8$^{\circ}C$/min, the organic-inorganic composites were synthesized. Microstructural evolution of the composites was characterized by DSC, IR spectrocopy, UV/VIS spectroscopy, and TEM. Elimination of the polymer precursor and degradation of the polymer were observed by DSC and Si-O and trans C=C absorption peaks were identified by IR spectra. The polymer was found to be successfully incorporated into the glass matrix and it was confirmed by the absorption peaks from the polymer in the UV/VIS spectra and the TEM results. The absorption peak of the composites was found to shift toward short wavelength side compared to that of the pure polymer and the amount of the blue shift increased with increasing the heat treatment temperature and heat treatment time and with decreasing the heating rate.

• Clean Technology
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• v.12 no.3
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• pp.145-150
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• 2006

Electrolysis of aqueous solution produces hydroxide ions and proton ions for the hydrolysis of reactive organic compounds, and oxidizing agent such as hypochlorite ions for the oxidative decomposition of organic chemicals. Electrolytic decomposition of dying chemicals was tested with our custom made system, and analyzed by HPLC and UV-VIS spectrophotometer. The electrolytic system could decompose dying chemicals with very high reactivity and low cost. Disposal of byproduct and refill of reactant during electrolysis was not necessary. Decomposition time of dying chemicals is compared under similar conditions, and application to water purification is discussed.