• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.315-323
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• 1998

$TiO_2$films of rutile and anatase phase have been prepared on silica glass substrates by the sol-gel method using $Ti(i-OC_3H_7)_4$. The effect of additives on the polymorph of $TiO_2$film has been examined in view of degree of crystallization. Third-order nonlinear optical properties of the both film have been investigated by the third harmonic generation method. The measured 3rd order nonlinear optical susceptibility of rutile and anatase thin films were about $1.4{\times}10^{-12}$ and $9.7{\times}10^{-13}$ esu, respectively.

• Tribology and Lubricants
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• v.22 no.5
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• pp.282-289
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• 2006

This paper is to investigate the wear behaviors of two type ceramics, $Al_{2}O_{3}\;and\;TiO_{2}$, by coated plasma thermal spray method under the lubricative environment. The lubricative environments are grease fluids, a general hydraulic fluids, and bearing fluids. The wear testing machine used a pin on disk type. Wear characteristics, which were friction force, friction coefficient and the specific wear rate, according to the lubricative environments were obtained at the four kinds of load and sliding velocity is 0.2 m/sec. After the wear experiments, the wear surfaces of the each test specimen were observed by a scanning electronic microscope.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.7-13
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• 2007

To produce stable polymer coating layer using the interaction between metal stent and polymer layer, Ahx-HSAB was synthesized by coupling 6-aminoheanoic acid (Ahx) with N-Hydroxy succinimidyl 4-azidobenzonate (HSAB) containing photo reactive group. Then, Ahx-HSAB was applied to self·assembled monolayer (SAM) on $TiO_2$-coated surface, since one end of Ahx-HSAB was carboxyl acid which was known to be able to interact with $TiO_2$ surface. That SAM layer was incubated in 1% polycaprolacton (PCL) solution and photoreacted by ultraviolet light (254 nm) to produce the chemical bond between SAM and polymer layer, followed by PCL polymer coating ({\sim}5\;{\mu}m$) by the method of spray coating. The surface change was investigated by measuring of contact angle of the surface. The contact angle values of stainless steel (SS) surface, $TiO_2$-coated surface, SAM layer by Ahx-HSAB, photoreacted surface with PCL and PCL layer by spray coating were 70.48${\pm}$1.89, 38.57${\pm}$3.31, 60.14${\pm}$2.21, 54.91${\pm}$2.70 and 56.47${\pm}$2.12, respectively. The stability of polymer layers was tested by incubation of PCL-coated plates in 0.1M PBS buffer (pH 7.4, 0.05%, Tween 80) with vigorous shaking (200 rpm). While the poiymer layer prepared by these processes showed the intact surface morphology over 3 days, the polymer layers prepared by spray coating of PCL onto SS plate (control 1) and $TiO_2$-coated SS plate (control 2) were Peeled off in 3 days. Thus, the polymer coating method using SAM and photoreaction seems to be a effective method to obtain the stable polymer layer onto SS surface.

• Textile Coloration and Finishing
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• v.15 no.3
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• pp.161-167
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• 2003

The preparations of deodorizing fibers using $TiO_2$ have been investigated. The fibers were coated with $TiO_2$ for the purpose of deodorizing by dipping fibers into the $TiO_2$ sol solutions and calcined at $450^\circ{C}$, $500^\circ{C}$ and $750^\circ{C}$ for 1 h after coating. The surface structure of the coated fibers was studied with XRD on the different preparation conditions of calcination temperatures. The deodorizing function of the prepared fibers was studied by the determination of the decomposing capability for $NH_3,\;CH_3SH\;and\;CH_3CHO$. The deodorant activity(D.A.) of these deodoriBing fibers was measured by chromogenic gas detector tubes. The deodorizing effect of the prepared fibers were shown to be similar for the three model compounds; 5wt% $TiO_2$ sol solution calcined at $450^\circ{C}$ < 5 wt% $TiO_2$ sol solution calcined at $500^\circ{C}$< 5 wt% TiO$_2$ sol solution calcined at $750^\circ{C}$.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3767-3771
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• 2012

In this study, we investigate the potential use of $TiO_2@SiO_2$ and $ZnO@SiO_2$ core/shell nanoparticles (NPs) as effective UV shielding agent. In the typical synthesis, $SiO_2$ was coated over different types of $TiO_2$ (anatase and rutile) and ZnO by sol-gel method. The synthesized $TiO_2@SiO_2$ and $ZnO@SiO_2$ NPs were characterized by UV-Vis, XRD, SEM and TEM. The UV-vis absorbance and transmittance spectra of core@shell NPs showed an efficient blocking effect in the UV region and more than 90% transmittance in the visible region. XRD and SAED studies confirmed the formation of amorphous $SiO_2$ coated over the $TiO_2$ and ZnO NPs. The FESEM and TEM images shows that coating of $SiO_2$ over the surface of anatase, rutile $TiO_2$ and ZnO NPs resulted in the increase in particle size by ~30 nm. In order to study the UV light shielding capability of the samples, photocatalytic degradation of methylene blue dye on $TiO_2@SiO_2$ and $ZnO@SiO_2$ NPs was performed. Photocatalytic activity for both types of $TiO_2$ NPs was partially suppressed. In comparison, the photocatalytic activity of ZnO almost vanished after the $SiO_2$ coating.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.183-183
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• 1999

Slurry sol(30at% anatase TiO$_2$)을 이용하여 스핀코팅으로 유리기판에 TiO$_2$박막을 제조하였다. 박막의 두께는 코팅주기의 횟수로 조절하였다. 한 코팅주기는 스핀코팅, 건조, 열처리를 포함한다. 박막의 반응성은 막 위에서의 자외선강도가 0.4mW/$\textrm{cm}^2$인 조건에서 벤젠기체의 광분해 속도를 통해 조사하였다. 박막의 두께가 증가할수록 표면적인 증가로 인해 반응성은 증가하였으며, 4$\mu\textrm{m}$정도이상의 두께에서 반응성은 더 이상 증가되지 않았다. porous한 TiO$_2$박막은 비교적 넓은 유효 표면적을 가지고 있으며, 그것은 두께증가에 따라 반응속도를 결정하는 결과를 낳았다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.143-143
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• 2002

• Membrane Journal
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• v.22 no.1
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• pp.8-15
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• 2012

Tubular $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ membranes with $La_{0.6}Sr_{0.4}Ti_{0.3}Fe_{0.7}O_{3-{\delta}}$ porous coating layer were prepared by extrusion and dip coating technique. XRD and SEM result showed the tubular membrane possessed the perovskite structure and porouscoating layer (thickness= about $2{\mu}m$) in surface. The oxygen permeation test was measured at condition of ambient air (feed side) and vacuum (permeate side) in the temperature range from 750 to $950^{\circ}C$. The oxygen permeation flux of $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ tubular membrane with $La_{0.6}Sr_{0.4}Ti_{0.3}Fe_{0.7}O_{3-{\delta}}$ porous coating layer reached maximum $3.2mL/min{\cdot}cm^2$ at $950^{\circ}C$ and was higher than non-coated $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ tubular membrane. Long-term stability test result indicated that the oxygen permeation flux was quite stable during the 11 day.

• Journal of the Korean Applied Science and Technology
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• v.23 no.3
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• pp.243-251
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• 2006

Field emission display(FED) is actively investigated in view of the development of full color flat-panel display, which can replace some cathode-ray tube(CRT). Thus, the development of new phosphors appropriate for FED is urgently needed and has been actively investigated. In this work, $SrTiO_3:Pr^{3+}$ phosphor was prepared by sol-gel method and the coating was applied by sol-gel method combined with sonication on these phosphor's surface into diluted precursor solution. It was found that very fine particles of coating material were formed on phosphor's surface. The luminescent intensity of $SrTiO_3:Pr^{3+}$ phosphor coated with $SiO_2$ and $Al_2O_3$ was considerably increased without any noticeable change in color chromaticity. The optimum concentration of coating material was found to be 1wt% and the optimum pH value of the solution was 10.

• International Journal of Highway Engineering
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• v.19 no.1
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• pp.53-62
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• 2017

PURPOSES : This research was a fundamental study on the application of an integral $TiO_2$ solution to asphalt concrete pavement. The integral $TiO_2$ solution was produced in pilot production equipment; application of the integral $TiO_2$ solution to asphalt pavement was conducted to examine the pollution-reducing capability of photocatalytic compounds such as $TiO_2$. The photocatalytic $TiO_2$ reacted with air pollutants, converting them into small amounts of relatively benign molecules. METHODS : In this study, laboratory experiments were conducted using five various testing methods. Tensile strength ratio (TSR) and British pendulum test (BPT) were conducted in order to evaluate the properties of asphalt pavement subsequent to the integral $TiO_2$ solution coating. In addition, methylene blue testing, a measurement of nitrate on the coated pavement, and nitrogen oxide (NOx) reduction testing were conducted in order to evaluate photocatalytic reaction. Lastly, a UV-A lamp was used as a light source for photocatalytic reactions. RESULTS : Test results indicated no change in the properties of asphalt pavement following the integral $TiO_2$ solution coating. In order to evaluate the performance of asphalt pavement as a function of $TiO_2$, the moisture susceptibility and skid resistance were investigated. The moisture susceptibility and skid resistance satisfied there quirements related to pavement quality and safety specification. Furthermore, the effects of reduction of air pollution were significantly improved as determined via the methylene blue test and NOx reduction test. The $TiO_2$-paved asphalt specimen exhibited approximately 43% reduction of NOx. CONCLUSIONS : This study has suggested that applying $TiO_2$ rarely impacts asphalt pavement performance measures such as moisture susceptibility and skid resistance, and that its application may be a better means of reducing air pollution. Further studies, such as proper $TiO_2$ dosage rates and compatibility with various pavement types, are required to broaden and generalize its application.