• 한국재료학회지
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• 제24권12호
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• pp.710-714
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• 2014

The effect of titanium dioxide ($TiO_2$) on the properties of color conversion glasses was examined for glasses based on $BaO-ZnO-B_2O_3-SiO_2$. One glass sample, containing 25 mol% of each component, was used as a reference; the other three glass samples contained 1, 3, and 5 mol% $TiO_2$, respectively. The four color conversion glass samples were prepared by sintering a mixture of glass frits and a $YAG:Ce^+$ phosphor. The characteristics of the color conversion glass samples, such as luminous efficacy, luminance, CIE (Commission International de I'Eclairage) chromaticity, CCT (Correlated Color Temperature), and CRI (Color Rendering Index) were analyzed according to the PL spectrum. The refractive index of the glass samples was found to increase with the titanium dioxide content. In conclusion, luminous efficacy of color conversion glasses increased as the content of $TiO_2$ was raised in the glass matrix.

• 한국세라믹학회지
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• 제45권4호
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• pp.196-203
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• 2008

Metal-carbon/$TiO_2$ composite photocatalysts were thermally synthesized through the mixing of anatase to metal(Cu, Zn) containing phenol resin in an ethanol solvent coagulation method. The BET surface area increases, with the increase depending on the amount of metal salt used. From SEM images, metal components and carbon derived from phenol resin that contains metal was homogeneously distributed to composite particles with porosity. XRD patterns revealed that metal and titanium dioxide phase can be identified for metal-carbon/$TiO_2$ composites, however, the diffraction peaks of carbon were not observed due to the low carbon content on the $TiO_2$ surfaces and due to the low crystallinity of the amorphous carbon. The results of a chemical elemental analysis of the metal-carbon/$TiO_2$ composites showed that most of the spectra for these samples gave stronger peaks for C, O, treated metal components and Ti metal compared to that of any other elements. According to photocatalytic results, the MB degradation can be attributed to the three types of synergetic effect: photocatalysis, adsorptivity and electron transfer, according to the light absorption between the supporter $TiO_2$, metal species, and carbon layers.

• 한국세라믹학회지
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• 제30권3호
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• pp.222-228
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• 1993

In order to obtian TiO2 fine powder of high purity, the new method which is different from the sulfate process and the chloride one was employed. TiO2 was syntehsized by the reaction between elemental titanium particles and H2O2 solutiosn at 30~7$0^{\circ}C$, and then TiO2 powder was characterized using XRD, SEM, TEM, DTA and FT-IR. It was found that the initial reaction rate was fast at a high temperature due to the high generation of activated oxygen associated with thedecomposition of H2O2. However, the reaction was slowly proceeded at a low temperature due to slow decomposition of H2O2. In this experimental range, the optimum temeprature was ocnsidered to be about 5$0^{\circ}C$. The primary particles of the hydrous titanium dioxide (TiO2 gel) before aging were spherical, and their mean sizes were about 50nm. The similar shapes and sizes were observed with calcinatin at 40$0^{\circ}C$. The FT-IR spectrum of Ti-OH in the TiO2 gel powder appeared at around 3380cm-1, 1630cm-1 and 530cm-1. This gel powder was crystallized into the anatase type TiO2 at 300~40$0^{\circ}C$.

• 한국응용과학기술학회지
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• 제24권1호
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• pp.1-9
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• 2007

It prepared the $TiO_2$ powder which has photo-catalytic activity in the visible-light by the wet process with titanium oxysulfate. The titanium $dioxide(TiO_2)$ by the wet process creates a new absorption band in the visible light region, and is expected to create photocatalytic activity in this region. Anatase $TiO_2$ powder which has photocatalytic activity in the visible light region, is treated using microwave and radio-frequency(RF) plasma. But, the $TiO_2$ powder for the visible light region, which also can be easily produced by wet process. The wet process $TiO_2$ absorbed visible light between 400nm and 600nm, and showed a high activity in this region, as measured by the oxidation removal of aceton from the gas phase. The AH-380 sample appears the yellow color to be strong, the catalytic activity in the visible ray was excellent in comparison with the plasma-treated $TiO_2$. The AH-380 $TiO_2$ powder, which can be easily produced on a large scale, is expected to have higher efficiency in utilizing solar energy than the plasma-treated $TiO_2$ powder.

• 한국응용과학기술학회지
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• 제27권1호
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• pp.56-60
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• 2010

Titanium dioxide particles are used as photocatalysts, sensors, adsorbents and catalyst. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 0.5~2.0 wt% EU-S133D, Titanium dioxide / Acrylate core-shell polymerization was carried out on the surface of Titanium dioxide particle without forming the new Titanium dioxide particle during acrylate shell polymerized in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer(TGA) and morphology of latex by scanning electron microscope(SEM).

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2849-2853
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• 2010

A method to improve the photocatalytic activity of titanium dioxide by modification with a sensitizer and a metal oxide is proposed. To achieve this goal, we used metal oxides as dopants. In particular, $CaWO_4$ and $Gd_2O_2S$:Tb were used because their 2.6 eV and 2.2 eV band gap energy and optical properties have a large positive effect on photocatalysis. The improvement in the photocatalytic activity of $TiO_2$ modified with $Gd_2O_2S$:Tb under ultraviolet light irradiation is described in a previous study. The present work focuses on the sensitization of metal oxide-modified $TiO_2$. Having observed the ultraviolet-visible absorption spectra of 3,4,9,10-Perylenetetracarboxylic diimide in the wide visible-light region from 400 nm to 650 nm and the broad peaks in its photoluminescence spectra at 695 nm and 717 nm, we decided to use this perylene dye to sensitize modified $TiO_2$ to enhance its activity as a visible-light harvesting photocatalyst. We also explored the positive effects thin-film surface changes stemming from ultraviolet pre-treatment have on photocatalytic activity. Finally, we subjected several metal oxide-modified $TiO_2$ products sensitized by the perylene dye to ultraviolet pre-treatment, obtaining the most active photocatalysts.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1284-1287
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• 2007

Titanium dioxide ($TiO_2$) is promising candidate for fabricating blocking layer of gate dielectrics in non-volatile memory (NVM). In this work, we investigated $TiO_2$ as high dielectric constant material instead of silicon dioxide ($SiO_2$), which is generally used as blocking layer for NVM.

• Advances in nano research
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• 제11권6호
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• pp.641-648
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• 2021

In this article, the dynamic parameters (frequencies, mode shapes, damping ratios) of the scaled concrete structure and the dynamic parameters (frequencies, mode shapes, damping ratios) of the entire outer surface of titanium dioxide, 80 micron in thickness are compared using operational modal analysis method. Ambient excitation was provided from micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition (EFDD) was used for the output only modal identification. From this study, a good correlation between mode shapes was found. Titanium dioxide applied to the entire outer surface of the scaled concrete structure has an average of 11.78% difference in frequency values and 10.15% in damping ratios, proving that nanomaterials can be used to increase rigidity in structures, in other words, for reinforcement. Another important result determined in the study was the observation of the adherence of titanium dioxide and similar nanomaterials mentioned in the introduction to concrete structure surfaces was at the highest level.

• Advances in nano research
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• 제12권1호
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• pp.65-72
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• 2022

The dynamic properties (frequencies, mode shapes, damping ratios) of the scaled WPC warehouse are compared using the operational modal analysis approach to the dynamic parameters (frequencies, mode shapes, damping ratios) of the full outer surface of titanium dioxide, 70 micron in thickness. Micro tremor ambient vibration data on ground level was used to provide ambient excitation. For the output-only modal identification, Enhanced Frequency Domain Decomposition (EFDD) was used. This study discovered a strong correlation between mode shapes. Titanium dioxide applied to the entire outer surface of the scaled WPC warehouse results in an average 14.05 percent difference in frequency values and 7.61 percent difference in damping ratios, demonstrating that nanomaterials can be used to increase rigidity in structures, or for reinforcement. Another significant finding in the study was the highest level of adherence of titanium dioxide and similar nanomaterials mentioned in the introduction to WPC structure surfaces.

• 한국산학기술학회논문지
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• 제4권1호
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• pp.13-16
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• 2003

열산화막으로 성장시킨 TiO₂/Ti에 70kev의 에너지로 N/sup +/ion 주입을 하고 이때 도우즈 범위를 0, 2, 5, 10×10/sup 17//cm²로 실시하였다. 한편, 이온주입에 따른 표면손상의 회복을 위해 각각 600℃∼2 hr동안 Ar분위기에서 실시하였다. N/sup +/ 도우즈 앙과 열처리에 따라 TiO₂ 색변화, 표면조도, 경도변화를 확인하여 의장용 재료로서의 Ti의 새로운 발색 가능성을 확인하였다. 기존 티타늄 산화층에 N/sup +/ 이온을 주입한 결과 도우즈 증가에 따라 갈색위주의 색변화가 가능하였고, 광택을 나타내는 표면조도는 열처리에 의해서 개선이 가능하였다. 한편 이온주입에 따른 경도는 열처리에 의해 10% 정도 향상이 가능하였다.