• 한국표면공학회지
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• 제50권1호
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• pp.35-41
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• 2017

$TiO_2$, $Al_2O_3$, and $TiO_2-Al_2O_3$ nanolaminated films were grown by atomic layer deposition (ALD) on the 316L stainless steel (SS316L) substrates at a temperature of $150^{\circ}C$. The growth kinetics of $ALD-TiO_2$ and $Al_2O_3$ thin films were systematically investigated in order to precisely control the thickness of each layers in the $TiO_2-Al_2O_3$ nanolaminated films using a high-resolution transmission electron microscopy. And, the exact deposition rates of $ALD-TiO_2$ on $Al_2O_3$ surface and $ALD-Al_2O_3$ on $TiO_2$ surface were revealed to be 0.0284 nm/cycle and 0.11 nm/cycle, respectively. At given growth conditions, the microstructures of $TiO_2$, $Al_2O_3$ and $TiO_2-Al_2O_3$ nanolaminated films were amorphous. The potentiodynamic polarization test revealed that the $TiO_2-Al_2O_3$ nanolaminated film coated SS316L had a best corrosion resistance, although all ALDcoated SS316L exhibited a clear improvement of the corrosion resistance compared with a bare SS316L.

• 한국광학회지
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• 제5권1호
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• pp.9-17
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• 1994

Ar 이온빔 보조 증착법(IBAD)으로 제작한 $TiO_2$ 박막의 광학적 특성을 연구하였다. 포락선 방법으로 측정한 단층 IBAD TiO2 박막의 굴절률은 이온빔을 사용하지 않은 보통 $TiO_2$ 박막보다 증가하여 bulk의 값에 보다 가까웠으며, 진공과 공기 중에서 투과 파장 영역의 이동을 측정하여 조사한 단층 IBAD 박막의 조밀도는 보통 박막보다 현격히 증가하였다. 이온빔 보조 증착법으로 $(TiO_2/SiO_2)$ 다층 박막 간섭필터를 제작하였고, 진공과 공기 중에서 각각 간섭 필터의 최고 투과 파장의 이동을 측정하였다. IBAD 간섭 필터의 파장 이동량은 보통 간섭필터에 비해 무시할 수 있을 정도로 작아 IBAD 박막의 조밀도가 증가하고 광학적으로 안정된 것을 알 수 있었다. 또한 IBAD $TiO_2$ 박막과 보통 $TiO_2$ 박막 모두 원소 조성비는 정상이었으며 결정 구조는 비정질이었다.

• 한국진공학회지
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• 제7권3호
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• pp.208-213
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• 1998

최근 셀리사이드(salicide) 제조시 $COSiO_2$의 에피텍셜 성장을 돕기 위하여 Ti층을 삽 입한 Co/Ti/Si 이중층 구조의 실리사이드화가 관심을 끌고 있다. Co/Ti 이중층을 이용한 salicide 트랜지스터가 성공적으로 만들어지기 위해서는 gate 주위의 spacer oxide위에 증착 된 Co/Ti 이중층을 급속열처리할 때 Co/Ti와 $SiO_2$간의 계면에서의 상호반응에 대하여 조사 하였다. Co/Ti 이중층은 $600^{\circ}C$에서 열처리한 후 면저항이 급격하게 증가하기 시작하였는데, 이것은 Co층이 $SiO_2$와의 계면에너지를 줄이기 위하여 응집되기 때문이다. 이때 Co/Ti의 열 처리후 Ti에 의하여 $SiO_2$기판의 일부가 분해됨으로써 절연체의 Ti산화물이 형성되었으나, 이외의 도전성 반응부산물은 발견되지 않았다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.929-935
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• 2014

Two types of nanosized titanium dioxide, anatase ($anTiO_2$) and rutile ($rnTiO_2$), are widely used in industry, commercial products and biosystems. $TiO_2$ has been evaluated as a Group 2B carcinogen. Previous reports indicated that $anTiO_2$ is less toxic than $rnTiO_2$, however, under ultraviolet irradiation $anTiO_2$ is more toxic than $rnTiO_2$ in vitro because of differences in their crystal structures. In the present study, we compared the in vivo and in vitro toxic effects induced by $anTiO_2$ and $rnTiO_2$. Female SD rats were treated with $500{\mu}g/ml$ of $anTiO_2$ or $rnTiO_2$ suspensions by intra-pulmonary spraying 8 times over a two week period. In the lung, treatment with $anTiO_2$ or $rnTiO_2$ increased alveolar macrophage numbers and levels of 8-hydroxydeoxyguanosine (8-OHdG); these increases tended to be lower in the $anTiO_2$ treated group compared to the $rnTiO_2$ treated group. Expression of $MIP1{\alpha}$ mRNA and protein in lung tissues treated with $anTiO_2$ and $rnTiO_2$ was also significantly up-regulated, with $MIP1{\alpha}$ mRNA and protein expression significantly lower in the $anTiO_2$ group than in the $rnTiO_2$ group. In cell culture of primary alveolar macrophages (PAM) treated with $anTiO_2$ and $rnTiO_2$, expression of $MIP1{\alpha}$ mRNA in the PAM and protein in the culture media was significantly higher than in control cultures. Similarly to the in vivo results, $MIP1{\alpha}$ mRNA and protein expression was significantly lower in the $anTiO_2$ treated cultures compared to the $rnTiO_2$ treated cultures. Furthermore, conditioned cell culture media from PAM cultures treated with $anTiO_2$ had less effect on A549 cell proliferation compared to conditioned media from cultures treated with $rnTiO_2$. However, no significant difference was found in the toxicological effects on cell viability of ultra violet irradiated $anTiO_2$ and $rnTiO_2$. In conclusion, our results indicate that $anTiO_2$ is less potent in induction of alveolar macrophage infiltration, 8-OHdG and $MIP1{\alpha}$ expression in the lung, and growth stimulation of A549 cells in vitro than $rnTiO_2$.

• 전기화학회지
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• 제17권1호
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• pp.13-17
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• 2014

The $TiO_2$ nanotube/Ti electrode are used as an anode in thin-film lithium microbatteries is known to have high oxidation-reduction potential of 1.8 V (vs. $Li/Li^+$). It can prevent from dendrite growth of lithium during charging. The $TiO_2$ nanotube/Ti electrode was prepared by anodizing at constant voltages for thin-film lithium microbatteries. The capacities of $TiO_2$ nanotube/Ti anode prepared by anodizing at 10 V, 20 V and 30 V were observed to be $23.9{\mu}Ah\;cm^{-2}$, $43.1{\mu}Ah\;cm^{-2}$ and $74.0{\mu}Ah\;cm^{-2}$. We identified it was found that the capacity of $TiO_2$ nanotube/Ti increases with increasing anodizing voltage and the anatase structure of $TiO_2$ nanotube/Ti compared with amorphous structure has batter cycle performance than amorphous $TiO_2$ nanotube/Ti.

• 한국산학기술학회논문지
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• 제1권2호
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• pp.57-62
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• 2000

Trichloroethvlene(TCE)의 수용액 내에서 광분해 반응을 연구하였다. 광촉매 TiO₂의 표면특성은 XRD, SEM 및 BET를 사용하여 선행연구[23]에서 고찰하였으며 Aldrich TiO₂는 100% anatase, Degussa 에서 제조한 P25-TiO₂는 75% anatase와 25% rutile의 혼합구조(structure)를 가짐을 알 수 있었다. 본 연구에서는 TCE 분해반응의 최적조건을 선정하기 위하여 광촉매의 사용량, 분해반응시 혼합용액의 순환유속, TCE의 초기농도 및 광촉매 TiO₂의 구조가 광분해 반응에 미치는 영향을 자세히 고찰하였다. 실험결과 증류수 1 L를 기준으로 무게비 0.1 wt%의 광촉매를 사용하여 증류수와 TCE의 혼합용액을 200 cc/min로 순환시켰을 때 분해활성이 가장 좋음을 알 수 있었으며 일반적으로 anatase 구조가 rutile구조를 가진 광촉매 보다 높은 활성을 보였다. 특히 anatase와 rutile의 혼합구조를 가진 Degussa P25-TiO₂가 가장 좋은 활성을 보였으며 이는 작은 입자크기와 큰 비표면적에 기인한 결과로 보인다.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3355-3360
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• 2012

To promote the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs), graphene is introduced as a working electrode with $TiO_2$ in this study, because it has great transparency and very good conductivity. XRD patterns indicate the presence of graphene and $TiO_2$ particles in graphene-linked $TiO_2$ samples. Moreover, TEM pictures also show that the nano-sized $TiO_2$ particles are highly dispersed and well-linked onto the thin layered graphene. On the basis of the UV-visible spectra, the band gaps of $TiO_2$, 1.0 wt % graphene-$TiO_2$, 5.0 wt % graphene-$TiO_2$, and 10.0 wt % graphene-$TiO_2$ are 3.16, 2.94, 2.25, and 2.11 eV, respectively. Compared to pure $TiO_2$, the energy conversion efficiency was enhanced considerably by the application of graphene-linked $TiO_2$ anode films in the DSSCs to approximately 6.05% for 0.1 wt % graphene-$TiO_2$ with N719 dye (10.0 mm film thickness and $5.0mm{\times}5.0mm$ cell area) under $100mW/cm^2$ of simulated sunlight. The quantum efficiency was the highest when 1.0 wt % of graphene was used. In impedance curves, the resistance was smallest for 1.0 wt % graphene-$TiO_2$-DSSC.

• 한국세라믹학회지
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• 제21권3호
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• pp.266-270
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• 1984

The photoelectrochemical properties of the reduced $TiO_2$ceramic electrodes are investigated varying the thickness of the electrodes and the amounts of $Sb_2O_3$ as dopant. As the thickness of the undoped. $TiO_2$ceramic electrode increases the photocurrent tends to decrease. However for the R-F sputtered $TiO_2$ thin film electrodes the photocurrent tends to increase to about 1$\mu\textrm{m}$ thick and then decreases with increasing thickness. For the $TiO_2$ ceramic electrodes doped with $Sb_2O_3$ the photocurrent decreases with inreasing the amounts of dopant and in the case of rapid cooling in air without reduction treatment the photocurrent shows lower value. Also visible light excitation is observed at 500~550(nm) wavelength for the $TiO_2$ ceramic electrodes doped with $Sb_2O_3$comparing wtih the $TiO_2$ ceramic electrodes (~420nm)

• 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.

• 한국포장학회지
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• 제23권2호
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• pp.67-74
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• 2017

In this work, the effects of nano $TiO_2$ on functionality and stability of low density polyethylene (LDPE) composite films were investigated for food packaging application. LDPE-nano $TiO_2$ composite films were prepared with various $TiO_2$ contents (0, 0.5, 1.0, 3.0 and 5.0wt%) by melt-extrusion and their basic properties such as crystallinity, chemical bonds and surface morphology were examined by XRD, FTIR and SEM. Ultraviolet (UV) light barrier property of as-prepared LDPE-nano $TiO_2$ composite films was also studied and the presence of nano $TiO_2$ resulted in significant improvement of UV light barrier compared to the pure LDPE film. To evaluate influence of nano $TiO_2$ on LDPE properties required as packaging material, thermal, mechanical, gas barrier and optical properties of LDPE-nano $TiO_2$ composite films were characterized with various analytical techniques including TGA, UTM, OTR, WVTR and UV-vis spectroscopy. As a result, except optical property of LDPE, no significant effects were found in other properties. Opacity of pure LDPE was greatly increased with increasing concentration of nano $TiO_2$.