• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.917-921
• /
• 2002

In this paper, we made different types of non-thermal plasma reactors such as Metal-particle reactor with $Al_2O_3$ to measure NOx removal characteristic and the dielectric effect for NOx removal. NOx removal rate is not so good when we use just dielectric of $Al_2O_3$ at the Metal-particle reactor, also we just put sludge pellets(100%) without Metal-particle reactor with $Al_2O_3$ and dielectric such as $TiO_2$, $BaTiO_3$ to measure the effect of sludge for NOx removal so that NOx removal rate is almost the same. However NOx removal rate is more than 90% in case of the reactor of composition shape used both dielectric of $Al_2O_3$ and sludge pellets at the same time. In case of the shape of plasma reactor with dielectric, the Metal-particle reactor with $Al_2O_3$, and the metal-particle reactor with both $Al_2O_3$ and dielectric such as $TiO_2$, $BaTiO_3$ at the same time, they are almost the same effect for NOx removal, so we made MNPR(Metal-particle Non-thermal Plasma Reactor with $Al_2O_3$) to reduce these kinds of demerits. Finally, we think MNPR should be much better than other reactors for NOx removal.

• Particle and aerosol research
• /
• v.6 no.4
• /
• pp.165-172
• /
• 2010

Titania is widely used as an effective photocatalyst for the photodegradation of environmental pollutants in air. In this study, novel N-doped $ZrO_2/TiO_2$ photocatalysts were synthesized via sol-gel method and characterized by UV-Vis spectrophotometer, transmission electron microscope, and X-ray diffractometer. N-doped $ZrO_2/TiO_2$ photocatalysts were nano-sized with an average particle size of about 20 nm. The XRD pattern of N-doped $ZrO_2/TiO_2$ photocatalysts showed both anatase and rutile phases. The photocatalytic activity of N-doped $ZrO_2/TiO_2$ photocatalysts was evaluated by degradation of NO under UV and visible light irradiation at various parameters such as amount of photocatalyst, concentration of NO, and intensity of light. The photocatalytic activity of N-doped $ZrO_2/TiO_2$ photocatalysts was effective for the enhancement of the degradation of NO and higher than that of $TiO_2$ photocatlysts under UV and visible light irradiation.

• Journal of the Korean Ceramic Society
• /
• v.23 no.1
• /
• pp.27-32
• /
• 1986

This study is aimed at synthsizing high dielectric material (Ba, Sr)$TiO_3$ through direct wet process. Pure and ultra fine particle of (Ba, Sr)$TiO_3$ Powder was synthesized from $BaCl_2$ $SrCl_2$ and TiCl4 aqeous solution at KOH Solution in the $N_2$ gas atmosphere. $BaCl_2$ $SrCl_2$ and TiCl4 were Mixed with the mole ratio of 1:9, 3:7:10, 5:5:10, 7:3:10, 9:1:10 and sythesized at 4$0^{\circ}C$~9$0^{\circ}C$ for 10min~15hrs. The particle size particle shape crystallinity and synthesis condition of (Ba, Sr)$TiO_3$ powder with the variation of temperature and reaction time in the aqueous solution studied by the exprimental instruments of DTA. TGA, X-ray diffratometer SEM.

• Journal of the Korean Ceramic Society
• /
• v.21 no.3
• /
• pp.278-282
• /
• 1984

Barium titanate powder was made by firing the complex hydroxide which had been synthesized with chemical wet process by the medium of $H_2O_2$. This experiment was done as following A mixed solution of $BaCl_2$, $TiCl_4$ and $H_2O_2$ with 1:1:10 mol ratio was prepared. Ammonium hydroxide was added into the mixed solution. In the range of pH 8-10 $BaTiO_3$ complex hydroxide was obtained and treated at room temperature 11$0^{\circ}C$, 20$0^{\circ}C$, 40$0^{\circ}C$ and $600^{\circ}C$. The results obtaiined from this experiment were as follows. At room temperature $BaTiO_3$ complex hydroxide was amorphous. Above 10$0^{\circ}C$ crystalline $BaTiO_3$ was obtained and particle size of $BaTiO_3$ was increased with elevated temperature. So the particle size of BaTiO3 could be controlled by the firing temperature. After treating $BaTiO_3$ complex hydroxide at 10$0^{\circ}C$ the average particle size of $BaTiO_3$ was 0.22$\mu\textrm{m}$.

• Journal of the Korean Ceramic Society
• /
• v.22 no.1
• /
• pp.19-24
• /
• 1985

The synthetic method was studied on the $SrTiO_3$ powder of pure and homogeneous ultra fine particle of $SrTiO_3$. Pure and ultra fine particle was synthesized from $Sr(OH)_2$.$8H_2O$ and Ti(OH) at 3$0^{\circ}C$~9$0^{\circ}C$ in the $N_2$ gas atmosphere.

• Journal of Industrial Technology
• /
• v.17
• /
• pp.241-247
• /
• 1997

A numerical model has been proposed for a diffusion flame reactor to manufacture ultrafine $TiO_2$ powders. The model equations such as mass balance equation, the 0th, 1st, and 2nd moment equations of aerosols were considered. The phenomena such as $TiCl_4$ reaction rate, $TiO_2$ nucleation rate and the coagulation of $TiO_2$ powders were included in the aerosol dynamic equation. It is found that the $TiO_2$ particle concentration becomes higher, as the inlet $TiCl_4$ concentration and the total gas flow rate increase, and also as the flame temperature decreases. The $TiO_2$ particle size increases, as the flame temperature and the inlet $TiCl_4$ concentration increase and the total gas flow rate decreases.

• Journal of Electrochemical Science and Technology
• /
• v.6 no.3
• /
• pp.75-80
• /
• 2015

We introduce a new synthesis method to prepare small TiO₂ nanoparticles with a narrow particle size distribution, which is achieved by electron beam (E-beam) irradiation. The effects of E-beam irradiation on the synthesis of TiO₂ nanoparticles and the electrochemical performance of TiO₂ nanoparticles as alternative anode materials for Li-ion batteries are investigated. The TiO₂ nanoparticles induced by E-beam irradiation present better cycling performance and rate capability than the TiO₂ nanoparticles synthesized by normal hydrolysis reaction. The better electrochemical performance is attributed to small particle size and narrow particle size distribution, resulting in the large surface area that provides innumerable reaction sites and short diffusion length for Li⁺ through TiO₂ nanoparticles.

• Journal of Powder Materials
• /
• v.13 no.4 s.57
• /
• pp.263-268
• /
• 2006

In this study, the colloidal stability and sedimentation behavior of crystalline $TiO_2$ particles (300nm) in various organic solvents have been investigated by means of a backscattered light flux profile (Turbiscan). The backscattered light flux profiles revealed that the $TiO_2$ nanoparticles were readily sedimented in water, methyl alcohol, and ethyl alcohol due to a flocculation-induced particle growth, while a particle coalescence and a sedimentation of the $TiO_2$ nanoparticles were hardly observed in isopropyl alcohol. The migration velocities of the $TiO_2$ particle were measured as around 6.15/min, 12.53 m/min, 6.51m/min, and 0.18m/min for water, methyl alcohol, ethyl alcohol, and isopropyl alcohol, respectively, showing a remarkably slow migration of the $TiO_2$ particles in isopropyl alcohol.

• The Korean Journal of Ceramics
• /
• v.3 no.1
• /
• pp.52-56
• /
• 1997

The Pt doped $TiO_2$ composite membranes were prepared by the sol-gel process. The Pt doped titania sol was peptized with hydrochloric acid in the pH range of 1.23 to 1.32 at 5$0^{\circ}C$. The average particle size of the Pt doped titania sol was shown to be below 15nm and well dispersed in the solution. XPS show the Pt elements continuous and homogeneous dispersed in the $TiO_2$ membrane. The mean particle size of the Pt doped $TiO_2$ composite membrane has smaller than that of the undoped $TiO_2$ composite membrane. The average pore size of the Pt doped $TiO_2$ composite membrane was increased from 58 to 193 $\AA$ with firing temperature changed from 550 to 85$0^{\circ}C$. It was observed that the Pt doped $TiO_2$ composite membranes showed crack-free and homogeneous microstructue as well as narrow particle size distribution up to above 75$0^{\circ}C$.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.8 no.4
• /
• pp.563-566
• /
• 1998

$BaTiO_3$ fine particles were prepared by hydrothermal process from titanium tetra-isoproproxide ($Ti(OiPr)_4$) and barium hexa-hydroxide ($Ba(OH)_2{cdot}8H_2O$) as raw materials. The fine particles were obtained at the temperature range of 160 to $185^{\circ}C$. The properties of $BaTiO_3$ particles were studied as a function of various parameters such as reaction temperature, reaction time and Ba/Ti ratio, etc. The average particle size of $BaTiO_3$ increased with increasing reaction temperature and time. After hydrothermal treatment at $170^{\circ}C$ for 8 h, the average particle size of $BaTiO_3$ was about 30 nm and the particle size distribution was narrow.