• Journal of the Korean Electrochemical Society
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• v.14 no.2
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• pp.77-82
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• 2011

The surface of $Li[Ni_{0.35}Co_{0.3}Mn_{0.35}]O_2$ cathode was modified by $[Li,La]TiO_3$ coating using pH controlled coating solution. At low pH values (acidic solution), cathode powders, which is oxides, have a positive surface charge, whereas, they have a negative surface charge at high pH values. As a result, their charge could affect the formation of the coating layer on the surface of cathode powder. To determine the optimal pH value, the surface coating of the pristine powder was carried out at various pH values of the coating solution. The surface morphology of coated samples was characterization by SEM and TEM analyses. Impedance analysis and cyclic voltammogram presented that internal resistance of the cell was dependent upon the pH of coating solution.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.1
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• pp.17-22
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• 2007

Metal-doped $TiO_2$ thin films were prepared on soda-lime-silica glass substrates by using a spin coating-pyrolysis process. As-deposited films were prefired at $500^{\circ}C$ or 10 min in air. Five-coated films were finally annealed at $600^{\circ}C$ for 30 min in air. High resolution X-ray diffraction, field emission scanning electron microscope and UV spectrophotometer were used to analyze film's property. The largest red shift in optical energy gap is obtained in the Fe-doped $TiO_2$ film.

• Journal of the Korean institute of surface engineering
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• v.40 no.4
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• pp.190-196
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• 2007

Dye sensitized solar cells(DSSC) are the most promising future energy resource due to their high energy efficiency, low production cost, and simple manufacturing process. But one problem in DSSC is short life time compared to silicon solar cells. This problem occurred from photocatalytic degradation of dye material by nanometer sized $TiO_2$ particles. To prevent dye degradation as well as to increase its life time, the transparent coating film is needed for UV blocking. In this study, we synthesized nanometer sized $TiO_2$ particles in sols by increasing its internal pressure up to 200 bar in autoclave at $120^{\circ}C$ for 10 hrs. The synthesized $TiO_2$ sols were all formed with brookite phase and their particle size was several nm to 30 nm. Synthesized $TiO_2$ sols were coated on the backside of fluorine doped tin oxide(FTO) glass by ink jet printing method. With increasing coating thickness by repeated ink jet coating, the absorbance of UV region (under 400 nm) also increases reasonably. Decomposition test of titania powders dispersed in 0.1 mM amaranth solution covered with $TiO_2$ coating glass shows more stable dye properties under UV irradiation, compared to that with as-received FTO glass.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.99-105
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• 2008

Core-shell structured $BaTiO_3$ powders were produced via nano-coating of $Cr_2O_3$ and $Mn_2O_3$ to barium titanate powder system for MLCCs. From preliminary experiments, the optimal solution reaction condition employing using $KMnO_4$, $K_2Cr_2O_4$ and sulfur was established. Not only powders of $Cr_2O_3$ and $Mn_2O_3$ were synthesized but also their coating on $BaTiO_3$ powders were peformed under the same reaction condition. The coating was carried out in two ways, one-step and two-step, and its results were characterized for comparison. Conclusively speaking, two oxide additives were coated onto the $BaTiO_3$ powder surface with high quality and excellent reaction yield even under mild condition, which indicates that the contents as well as the properties of additive shell layer can be precisely controlled with rather ease.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.7-11
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• 2000

The anti-reflective anti-static (ARAS) optical film is designed using absorbent materials such as ITO, $TiN_xW_y$, Ag by Essential Macleod program. [air ${\mid}TiN_xW_y{\mid}SiO_2{\mid}$ glass] two layer shows wide-band AR coating in the wavelength range of 450~700 nm. The reflectivity, transmittance of this coating are below 0.5%, about 75%, respectively. [air $SiO_2{\mid}TiO_2{\mid}SiO_2{\mid}$, ITO glass] layer can adjust reflectance of below 0.5% with above 97% transmittance. In the [air ${\mid}SiO_2{\mid}TiO_2{\mid}SiO_2{\mid}$ Ag glass] layer, the transmission can be controlled at above 96% with reflectance of 1~2%.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1895-1899
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• 2012

$SiO_2$-coated $TiO_2$ composite materials with enhanced photocatalytic activity under UV light was prepared by a simple catalytic hydrolysis method. XRD, TEM, UV-vis spectroscopy, Photoluminescence, FT-IR and XP spectra were used to characterize the prepared samples. The obvious shell-core structure was shown for obtained $SiO_2$@$TiO_2$ sample. The average thickness of the $SiO_2$ coating layer was 2-3 nm. The interaction between $SiO_2$ and $TiO_2$ restrained the recombination of excited electrons and holes. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under UV light. The photocatalytic activity of $SiO_2$@$TiO_2$ was much higher than that of P25 and mechanical mixing sample $SiO_2/TiO_2$. The possible mechanism for the photocatalysis was proposed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1998.11a
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• pp.73-74
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• 1998

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.217-222
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• 1998

Coating films of $SiO_2-TiO_2-AgO$ have been prepared on soda-lime-silica slide glasses and single crystal silicon wafer by the sol-gel method using a spin-coating technique. Commercially available tetraethyl orthosilicate, titanium trichloride, and silver-nitrates were used as starting materials. The heat treatment temperature of this coating films was $500^{\circ}C$ properly, obtained from TG-DTA result. The films with thickness of 310 nm were prepared by 5 times coating. In the case of l0 mol% AgO, the film showed a crack-free and smooth surface, but the higher Ago content exhibited the more pin hole and the segregated cluster of AgO. The IR absorbance of the films decreased in the range of 400 nm to 700 nm with the increase of annealing temperature. And the reflectance of the coating films decreased and the color was changed light yellow to white yellow with the increase of Ago content.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.777-782
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• 2008

Using ultrasonic-induced polymerization of pyrrole, mesoporous $TiO_2$ thin film with polypyrrole nanoparticles was prepared. Polypyrrole nanoparticles were ultrasonically synthesized in the mother solution of mesoporous $TiO_2$ before spin-coating. The polypyrrole particles were well dispersed in the solution. After spin-coating and calcinations process, the nanocomposite films have well-organized pore channels without pore-collapse, and polypyrrole nanoparticles are well dispersed in mesoporous $TiO_2$ matrix. The pore size and light absorbance of the mesoporous nanocomposite thin films were controlled by using different template materials, and by using different amount of pyrrole monomer, respectively.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.1-9
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• 2013

PURPOSES : About 35% of air pollutant is occurred from road transport. NOx is the primary pollutant. Recently, the importance of NOx removal has arisen in the world. $TiO_2$ is very efficient for removing NOx by photocatalytic reaction. The mechanism of removing NOx is the reaction of photocatalysis and solar energy. Therefore, $TiO_2$ in concrete need to be contacted with solar radiation to be activated. In general, $TiO_2$ concrete are produced by substitute $TiO_2$ as a part of concrete binder. However, 90% of $TiO_2$ in the photocatalysis can not contacted with the pollutant in the air and solar radiation. Coating and penetration method are attempted as the alternative of mixing method in order to locate $TiO_2$ to the surface of structure. METHODS : The goal of this study was to attempt to locate $TiO_2$ to the surface of concrete, so we can use the concrete in pavement construction. The distribution of $TiO_2$ along the depth were confirmed by basing on the comparison of $TiO_2$ compare by using the EDAX(Energy Dispersive X-ray Spectroscopy). RESULTS : $TiO_2$ were distributed within 3mm from concrete surface. This distribution of $TiO_2$ is desirable, since the $TiO_2$ induce photocatalysis are located to where they can be contacted with the air pollutant and solar radiation. CONCLUSIONS : Nano size $TiO_2$ is easily penetration in the top 3mm of concrete surface. By the penetration $TiO_2$ concrete can be produced with the use of only 10% of $TiO_2$, by comparing the mixing types.