• Applied Chemistry for Engineering
• /
• v.27 no.2
• /
• pp.205-209
• /
• 2016

The influence of titania nanorods with an average diameter of 10 nm and an average length of 30 nm on the electrohydrodynamic instability of block copolymer (polystyrene-b-poly(2-vinylpyridine)) thin film was investigated in this article. The presence of titania nanorods increased the dielectric constant of the film, which resulted in a systematic reduction in the wavelength of the surface instability. Cross-sectional transmission electron microscopy analysis indicated that the migration/aggregation of titania nanorods did not occur as a result of the applied electric field. This work can provide a simple route to the pattern formation using electrohydrodynamic instability with an aid of nanoparticles.

• Korean Journal of Dental Materials
• /
• v.44 no.1
• /
• pp.33-41
• /
• 2017

In this study, we prepared PLA-tetracycline complexes coated gold nanoparticle-titania nanotubes and estimated their infrared LASER mediated drug release in the abdominal region of ICR mouse. The results of UV-Vis spectrophotometer showed the highest absorbance at the wavelength of 530 nm and 809 nm indicating the existence of gold nanoparticles. EDX analysis showed that the amounts of gold nanoparticle coated on titania nanotubes were approximately 3.62-36.5 wt%. In vivo test resulted that the tetracycline release value of experimental groups (6.5 ng/mL) was higher than that of control group (5.8 ng/mL) on the condition of 30 minutes of LASER irradiation. Therefore, it is expected that PLA-tetracycline complexes coated gold nanoparticle-titania nanotubes have the feasibility in the field of infrared remote controlled drug device and overcome the limitation of location and time of drug release in dental implant.

• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1803-1805
• /
• 1999

The thermal expansion coefficient of the titania-fused silica glass$(TiO_2-SiO_2)$ called KLR-1.1 is known to $0{\pm}0.03$ ppm/K, while that of normal fused-silica glasses is about +0.5 ppm/K at room temperature. To analysis the dielectric properties of the KLR-1.1, the sample with diameter of 30 mm and thinkness of 1 mm is covered with gold film. Its relative permittivity and dissipation factor of KLR-1.1 is evaluated to $4.011{\pm}0.012(1\sigma)$ and $(4.86{\pm}0.02){\times}10^{-4}(1{\sigma})$ at 1 kHz respectively. The measurement techniques used and results are more discussed in this paper.

• Journal of Welding and Joining
• /
• v.9 no.3
• /
• pp.18-25
• /
• 1991

The purpose of this paper was to investigate the effect of deposition configuration on the mechanical properties of the flame sprayed titania ceramic coating. The sprayed deposition configuration was made in different five types with titania ceramic and Ni-base alloy on the mild steel substrate. The composite coating exhibited superior mechanical properties such as hardness, adhesive strength, thermal shock resistance and corrosion resistance, whereas the mixed coating proved to be more resistant to erosion. Especially graded coating, which consist of Ni-base alloy undercost, intermediate grade coat and titania ceramic overcost, showed excellent mechanical properties.

• Journal of Environmental Science International
• /
• v.11 no.9
• /
• pp.987-992
• /
• 2002

Nanosized titania sol has been produced by the controlled hydrolysis of titanium tetraisopropoxide(TTIP) in sodium bis(2-ethylhexyl)sulfosuccinate(AOT) reverse micelles. The physical properties, such as crystallite size and crystallinity according to R ratio have been investigated by FT-IR, XRD and UV-DRS. In addition, the photocatalytic degradation of bromate has been studied by using batch reactor in the presence of UV light in order to compare the photocatalytic activity of prepared nanosized titania. It is shown that the anatase structure appears in the 300~$600^{\circ}C$ calcination temperature range and the formation of anatase into rutile starts above $700^{\circ}C$. The crystallite size increases with increasing R ratio. In the photocatalytic degradation of bromate, the photocatalytic decomposition of bromate shows the decomposition rate increases with decreasing initial concentration of bromate and with increasing intensity of light.

• The Korean Journal of Ceramics
• /
• v.5 no.4
• /
• pp.386-389
• /
• 1999

Effect of high voltage screening was examined on mechanical strength of titania ceramics with two different surface roughness. Roughly finished sample showed degraded mechanical strength meaning that the introduced flaw played the role of starting point of mechanical fracture. On such sample, electrically weak parts were eliminated by applying a screening field. Mechanical strength measurement on survived parts revealed that after screening the Weibull plots bended to become a convex curve while plots at high strength region were almost the same. This result means that relatively low mechanical strength parts were eliminated by the electrical method. As a result the Weibull modulus calculated from all the data increased, demonstrating the effect of high voltage screening on titania ceramics containing fracture controlling surface flaws. Roles of the surface flaw such as a common weak spot for both failures are disscussed in relation to the electric field concentration similar to that of mechanical stress.

• Journal of Advanced Marine Engineering and Technology
• /
• v.15 no.3
• /
• pp.39-44
• /
• 1991

The purpose of this investigation is to examine the effects of spraying conditions on the mechanical properties of flame-sprayed titania ceramic coating layer. Titania ceramic was sprayed onto the mild steel substrate under the various spraying conditions. Spraying distances were 100, 150, 200, 250mm respectively and pinch air pressures were 0.2 0.3, 0.4 MPa at each spraying distance. The mechanical properties such as microhardness, adhesive strength and erosion wear resistance were tested for the specimens sprayed under the various spraying conditions above mentioned. The optimum operational conditions obtained through the experimental results were 150mm of spraying distance and 0.3 MPa of pinch air pressure.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.05a
• /
• pp.39-42
• /
• 2004

Ceramic membranes have attracted a great attention because they have excellent resistance to most organic solvents and can be used over a wide temperature range. Especially, titania (titanium oxide, TiO$_2$) shows excellent chemical resistance and can be used both acidic and alkali solutions, and therefore, titania is one of the most promising materials for the preparation of porous membranes; titania membranes having pore sizes in the range of nanofiltration (NF) to ultrafiltration (UF) membrane have been prepared by the sol-gel process (Tsuru 2001).(omitted)

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.50 no.12
• /
• pp.593-598
• /
• 2001

Transient liquid phase processing was investigated to decrease processing temperatures while maintaining useful piezoelectric properties in the lead zirconate titanate (PZT) system. Niobium oxide$(Nb_2O_5)$ modified crystalline PZT (PZTN) powder was combined with lead silicate $(PS; PbO-SiO_2)$ glass powder and crystalline titania, zirconia, and niobia. Firing above the melting temperature of the lead silicate $(PS; Tm \risingdotseq\; 714^{\circk}C)$ resulted in liquid phase densification of the PZTN followed by dissolution of the titania, zirconia, and niobia into the liquid phase, and crystallization of additional PZTN. The addition of crystalline titania, zirconia, and niobia to react with the lead oxide from the lead silicate phase resulted in an increase in the dielectric and Piezoelectric properties.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.12
• /
• pp.1303-1308
• /
• 2001

A series of catalysts, NiSO4/TiO2, for ethylene dimerization was prepared by the impregnation method using aqueous solution of nickel sulfate. On the basis of the results obtained from X-ray diffraction, the addition of NiSO4 shifted the transition of TiO2 from the anatase to the rutile phase toward higher temperatures due to the interaction between NiSO4 and TiO2. Nickel sulfate supported on titania was found to be very active even at room temperature. The high catalytic activity of NiSO4/TiO2 closely correlated with the increase of acidity and acid strength due to the addition of NiSO4. It is suggested that the active sites responsible for ethylene dimerization consist of low valent nickel, Ni+, with an acid.