• 약학회지
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• 제52권5호
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• pp.407-411
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• 2008

Phosphorylation plays the most important role in cell signaling mechanism. Various methods to identify the phosphorylation sites of proteins using tandem mass spectrometry (MS/MS) have been reported recently. Furthermore, the enrichment strategy such as Titanium dioxide ($TiO_2$) method should be combined with MS/MS analysis to effectively identify phosphorylation sites. It is necessary to optimize phosphopeptide-enrichment strategy, $TiO_2$ method in this study, due to the low amount of phosphorylated form followed by analyzing them by MS/MS. To evaluate the several conditions to enrich phosphopeptides using $TiO_2$ method, we used ${\apha}$-casein as a standard phosphoprotein and analyzed a representative phosphopeptide (VPQLEIVPNpSAEER) peak of MS spectrum. Batch is better than column method for binding and 300 g/l DHB in loading buffer is better than lower concentration of DHB. 3% TFA and pH 10.5 shows high efficiency of phosphopeptide-enrichment for washing and elution steps, respectively. Finally we identified various efficient conditions of phosphopeptide-enrichment method using $TiO_2$. This optimized method would assist in reliable identifying thousands of phosphorylation sites existed in low abundance from various complex proteins.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.60.2-60.2
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• 2010

A $TiO_2$ films in dye-sensitized solar cells was fabricated using $TiO_2$ colloidal sol prepared from titanium iso-propoxide used as a starting material by applying the sol-gel method. It was characterized by particle size analyzer, XRD, FE-SEM, and BET analysis. The adsorption isotherms of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$) and at three different pH (3, 5, 7). The adsorption kinetics of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$. The adsorption experimental data were correlated with Langmuir isotherm model and pseudo-second-order model. Also the isosteric enthalpies of dye adsorption were calculated by the Clausius-Clapeyron equation. In addition, the adsorption energy distribution functions which describe heterogeneous characteristics of nanocrystalline $TiO_2$ film surface were calculated by using the generalized nonlinear regularization method. We found that efficient adsorption of N719 dye from aqueous solution onto $TiO_2$ films can be successfully achieved by dye adsorption conditions and morphology of $TiO_2$ films.

• 한국세라믹학회지
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• 제24권6호
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• pp.579-585
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• 1987

The effects of flux KCl and dopant Nb2O5 on the PTCR characteristics of BaTiO3 prepared by molten salt synthesis method have been investigated. As the amount of dopant Nb2O5 is over the solubility limit in BaTiO3, the room-temperature resistivity increases, and the PTCR effect and the grain size decrease. The variation of the amount of flux KCl slightly influences on the room-temperature resistivity, PTCR effect and grain size in Nb2O5 doped BaTiO3, but BaTiO3 ceramics prepared by the method of molten salt synthesis show larger PTCR effect than those of conventional calcining of mixed oxides.

• 청정기술
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• 제26권4호
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• pp.304-310
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• 2020

다양한 건축재료에 광촉매(TiO2)를 적용하기 위하여 TiO2-mayenite를 제조하였다. TiO2는 졸-겔법을 사용하여 titanium isopropoxide (TTIP)와 urea를 1:1의 비율로 고정하여 합성하였다. 그 후 온도범위 400 - 700 ℃로 소성하여 온도에 따른 특성을 분석하였다. TiO2의 물리 및 화학적 특성은 BET, TGA 그리고 XRD를 통해 분석되었다. 질소산화물 제거 실험은 KS L ISO 22197-1에 의거하여 1 시간 동안의 NO의 농도변화를 측정하여 확인하였다. 제조된 입자들은 600 ℃ 이하에서 아나타제 결정구조를 나타내었고, TiO2 (urea)-400에서 2.35 µmol h-1의 가장 높은 질소산화물 제거율을 나타내었다. TiO2-mayenite는 TiO2 분산 용액을 스프레이하는 방법(s/s)과 졸-겔 상태의 용액을 스프레이 하는 방법(g/s)으로 제조하였다. BET와 XRD 분석을 통하여, 제조된 TiO2-mayenite는 졸-겔 상태의 용액을 스프레이 하여 제조한 5-TiO2 (g/s) 입자가 열처리에도 결정구조를 유지하는 것을 확인하였다. 또한 질소산화물 제거 실험에서도 5-TiO2 (g/s)-500 입자에서 0.55 µmol h-1의 가장 높은 제거율을 나타내었다. 결론적으로 TiO2-mayenite를 제조하기 위하여 TiO2는 졸-겔 상태에서 mayenite에 결합시켜야 결정구조를 유지하며, 높은 질소산화물 제거 능력을 나타내는 것을 확인하였다.

• 한국분말재료학회지
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• 제23권1호
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• pp.33-37
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• 2016

10 wt.% and 20 wt.%$Li-TiO_2$ composite powders are synthesized by a sol-gel method using titanium isopropoxide and $Li_2CO_3$ as precursors. The as-received amorphous 10 wt.%$Li-TiO_2$ composite powders crystallize into the anatase-type crystal structure upon calcination at $450^{\circ}C$, which then changes to the rutile phase at $750^{\circ}C$. The asreceived 20 wt%$Li-TiO_2$ composite powders, on the other hand, crystallize into the anatase-type structure. As the calcination temperature increases, the anatase $TiO_2$ phase gets transformed to the $LiTiO_2$ phase. The peaks for the samples obtained after calcination at $900^{\circ}C$ mainly exhibit the $LiTiO_2$ and $Li_2TiO_3$ phases. For a comparison of the photocatalytic activity, 10 wt.% and 20 wt.% $Li-TiO_2$ composite powders calcined at $450^{\circ}C$, $600^{\circ}C$, and $750^{\circ}C$ are used. The 20 wt.%$Li-TiO_2$ composite powders calcined at $600^{\circ}C$ show excellent efficiency for the removal of methylorange.

• 전기전자학회논문지
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• 제21권3호
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• pp.288-296
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• 2017

The enhancement of photoluminescence of Au-$TiO_2$ nanoparticles by surface plasmon resonance has been studied extensively by experiment in recent years. For the purpose of optimizing the photoluminescence property of Au-$TiO_2$ nanoparticles, the manufacturing parameters related to the Au nanoparticles and $TiO_2$ nanoparticles need to be considered. In this paper, Drude model and Maier's effective volume method are used to analyze the variation of the metal nanoparticle radius, separation between metal nanoparticle and dielectric molecule, and total absorption cross-section with original radiative efficiency on the photoluminescence property of Au-$TiO_2$ nanoparticles. The results show that to obtain the optimized enhancement factor for photoluminescence process, the size of Au nanoparticle is about 13 - 20 nm, the separation between Au nanoparticle and $TiO_2$ molecule is about 5 -15 nm, the total absorption cross-section of $TiO_2$ molecules is about $1-100nm^2$ and the original radiative efficiency of $TiO_2$ molecule is weak about 0.001- 0.1. With these fabrication parameters, the photoluminescence property of Au-$TiO_2$ nanoparticles can be enhanced several thousand times compared to traditional $TiO_2$ nanoparticles.

• 공업화학
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• 제23권3호
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• pp.293-296
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• 2012

항균 활성도를 조사하기 위해 이산화티탄미립자 표면에 나노메탈(Au, Ag)을 균일하게 도핑한 나노복합체($Ag-TiO_2,\;Au-TiO_2,\;Ag-TiO_2$@$TiO_x$)를 초음파환원법과 졸-겔 법으로 제조하였다. 이렇게 제조된 나노메탈-이산화티탄 복합체의 항균 활성도는 고체배지 표면에 나노복합체와 함께 E. coli를 도말하여 $37^{\circ}C$에서 배양한 후 생존된 콜로니 개수의 측정을 통해서 이루어졌다. 나노복합체의 초기 항균 효율은 나노메탈이 도핑된 이산화티탄미립자($Ag-TiO_2,\;Au-TiO_2,\;Ag-TiO_2$@$TiO_x$)) 복합체가 도핑하지 않은 이산화티탄미립자($TiO_2$)에 비해 높은 항균 효율을 나타내주었다. 이후, 나노복합체를 $4^{\circ}C$에서 보관 후 장기보관에 따른 항균특성을 비교해본 결과, 나노메탈만 도핑된 복합체($Ag-TiO_2,\;Au-TiO_2$)보다는 $Ag-TiO_2,$의 표면을 다시 산화티탄막으로 코팅한 복합체($Ag-TiO_2$@$TiO_x$)의 항균특성이 오랫동안 유지되는 것을 알수 있었다. 이는 산화티탄막으로 다시 코팅한 $Ag-TiO_2$@$TiO_x$의 경우에 Ag 나노메탈의 산화방지 및 나노복합체의 콜로이드 안정성 향상이 이루어졌기 때문으로 사료된다.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3317-3322
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• 2011

This study examines the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs) when nanometer-sized Zr (0.1, 0.5, and 1.0 mol %)-$TiO_2$ prepared using a solvothermal method is utilized as the working electrode material. The particle sizes observe in the transmission electron microscopy (TEM) images are < 30 nm in all samples. The absorption band is slightly broadened at the tail for the 0.1 mol % Zr-$TiO_2$, and the intensity of the photoluminescence (PL) curves of the Zr-incorporated $TiO_2$ is significantly smaller than that of the pure $TiO_2$. Compared to that using pure $TiO_2$, the energy conversion efficiency is enhanced considerably by the application of Zr-$TiO_2$ in the DSSCs to approximately 6.17% for 0.5 mol % Zr-$TiO_2$ with the N719 dye (10.0 ${\mu}m$ film thickness and 5.0 mm ${\times}$ 5.0 mm cell area) under 100 mW/$cm^2$ of simulated sunlight.

• 태양에너지
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• 제9권1호
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• pp.14-21
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• 1989

Preparation of $TiO_2$ Film by the Dip-coating Method and its Application to photo-electrochemical Electrodes. $TiO_2$ film of n-type semiconductor has been of great interest as a material for solar energy conversion. For its practical application, the dip-coating method has been applied to prepare $TiO_2$ (anatase) film on the nesa glass substrate. Films up to about $1.8{\mu}m$ in thickness can be obtained by repeating the operation, dipping $\to$ pulling up $\to$ drying $\to$ heating at $500^{\circ}C$ for 10 minute. Heating temperature at $500^{\circ}C$ was adopted to convert $TiO_2$ gels into $TiO_2$ crystalline films. The $TiO_2$ films showed the maximum photocurrent ($14mA/cm^2$) at the film thickness of about $1.8{\mu}m$. It was also found that the additional heating at $500^{\circ}C$ for about 20 minutes improved remarkably the photo current of the $TiO_2$ films.

• 한국전기전자재료학회논문지
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• 제25권4호
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• pp.315-320
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• 2012

In general, a photoelectrode in DSSC(dye sensitized solar cell) are fabricated by using the $TiO_2$ (Titanium dioxide) to realize high efficiency and the efficiency of DSSC is affected by the size, the shape and the property of $TiO_2$. We synthesized the crystalline $TiO_2$ by sol-gel method. In spite of many merits, only weakness for the sol-gel method is taking many process times. To solve this problem, we reduced the fabricating processes. The reduced process is the making process that is $TiO_2$ sol to $TiO_2$ powder with including of two heat treatment and two mixing. We could simplify the process by preparing $TiO_2$ sol to $TiO_2$ paste directly. As a result, DSSC fabrication process is simplified and we have obtained the efficiency best result 3.88% with $V_{OC}$=0.71 V, $J_{SC}=8.70\;mA/cm^{-2}$, and FF=62.37%, respectively.