Authors: Wei Lin, Jian Li Zhao, Junji Ommyoji, Akira Yamaguchi
Abstract: In order to develop an ideal material for the nozzle used in steel continuous casting
process, the hydration resistance of some CaO-containing complex oxides and CaO-NiO solid
solutions were investigated systematically. The hydration resistance of the complex oxides was CT
>CZ>CS>CF>CB3BTB2 B>CB2BS>>CB2BF>CB3BA>CAB2B>CaO. CT should be a promising material for the nozzle.
A large number of fine secondary-NiOss particles were separated from the CaOss crystal grains in
CaO-NiO solid solution and improved the hydration resistance.
2284
Abstract: Lightweight fine open-cell porous Si/SiC ceramic filter was fabricated using
polyurethane sponge. The thickness of the strut and the cell size of porous Si/SiC ceramics were
almost the same size of the original sponge. This porous ceramic was an ideal structure for
photocatalyst supports. The contact probability between photocatalyst and pollutant could be
easily increased by using this ceramic filter coated with photocatalyst. The TOC value of Orange
II solution, coloring matter, could decrease remarkably using this photocatalytic ceramic filter and
germicidal lamp.
2159
Authors: Jun He, Mike W. Finnis, Elizabeth C. Dickey, Susan B. Sinnott
Abstract: TiO2 has been intensively studied as a wide band-gap transition metal oxide partially due
to the multi-valence nature of its cation. Here, density-functional theory calculations within the
supercell approximation are carried out to determine the preferred charge state of point defects in
rutile TiO2. The first component of this work is to investigate the dependence of the defect
formation energies on supercell size and the electrostatic Makov-Payne correction. The results show
that the Makov-Payne correction improves the convergence of defect formation energies as a
function of supercell size for positively charged titanium interstitials and negatively charged
titanium vacancies. However, in the case of positively charged oxygen vacancies, applying the
Makov-Payne correction gives the wrong sign for the defect formation energy correction. This is
attributed to the shallow nature of the transition levels for this defect in TiO2. Finally, we combine
the calculated defect formation energies with thermodynamic data to evaluate the influence of
temperature on the relative stabilities of point defects. The results indicate that when the Makov-
Payne correction is applied, a stable charge transition occurs for titanium interstitials. In addition, as
the temperature increases, the dominant point defect in TiO2 changes from oxygen vacancies to
titanium interstitials.
1
Abstract: The coating of polymer surfaces with ceramics up to now is basically only accomplishable
by vacuum-based technologies such as sputtering, because the thermal load is low compared to
other methods such as sol-gel processing. Since the investment costs for the equipment required are
considerably high and the coating is limited to line-of sight deposition, simple and cost-effective
processing routes are sought.
In all higher organisms inorganic materials are synthesized at ambient temperatures under physiological
conditions. Therefore the study of biomineralization processes has gained considerable academic
attention in the last decades. One of the key features of inorganic material deposition in vito
is the interaction between supersaturated solutions and specifically modified surfaces.
Following this paradigm so-called bio-inspired approaches can be developed which go beyond the
current limitations of synthetic techniques. One example is the mineralization of planar polymer
surfaces with TiO2 at 50oC. Using polystyrene latex particles as templates, all four stages
commonly found in natural biomineralization can be emulated in a completely artificial system.
1246
Authors: Hidekazu Tanaka, Ikuyo Higashio, Keiichi Watanabe, Yoko Suyama
Abstract: Fibrous TiO2 with ca. 0.16 mm in width and 5 - 6 cm in length was prepared by drying a
suspension of monodispersed anatase particles at 363 K in air. The TiO2 fibers thus obtained were
thermally treated at the temperatures ranging from 363 to 1273 K for 1 h in air. Elevating the treating
temperature increases the crystallinity of anatase phase and reduces the specific surface area from 98
to 5 m2/g due to the sintering of particles. The rutile phase appears at 1273 K by transformation of
anatase phase. A photocatalytic activity of the fibers was examined by decomposition of methylene
blue (MB) in water under UV irradiation centered at 365 nm. The fibers decomposed the MB in
aqueous media under UV irradiation, indicating that the fibers possess a high photocatalytic activity.
The catalytic activity is considered to be enhanced on increasing the crystallinity of anatase phase,
nevertheless, that decreased with generation of rutile phase.
951
Authors: M. Lejeune, Thierry Chartier, C. Dossou-Yovo, R. Noguera
413
Authors: J.H. Kim, Nam Hee Lee, Hyo Jin Oh, Cho Rong Yoon, Wheung Whoe Kim, Jae Sung Song, C.J. Jeon, Sun Jae Kim
Abstract: An electrophoretic solution using TiO2 nano particles is the most promising candidate in
electronic paper industry because it offers various advantages such as ink-on-paper appearance, good
contrast ratio, wide viewing angle, image stability in the off-state and extremely low power
consumption. To prepare an electrophoretic solution of TiO2 nano particles with low apparent gravity
for electronic paper, TiO2 powders were mixed with polyethylene powders using high energy
planetary-mill in cyclohexane with low dielectric constant and transparency. The zeta-potential value
of raw TiO2 particles in cyclohexane was measured about -80mV but that of polyethylene-coated
TiO2 particles by milling was measured over -110mV, with showing good dispersibility by surfactant
attached to them. Thus it was possible to control surface charge on the TiO2 particle by using
optimum amount of surfactant after polyethylene coating on them for enhancement of dispersion
stability.
368
Authors: Hiroya Abe, Akira Kondo, Kosuke Takenaka, Yuichi Setsuhara, Makio Naito
Abstract: An apparatus which presents a mechanical milling with electric discharge is introduced.
As a model experiment, an anatase TiO2 nanopowder was processed by the method
using NH3(10%)/N2 gas. The influences of specific surface area, crystal structure, and
optical property were investigated. Relatively high specific surface areas exceeding
250m2/g were observed for all processed powders. The crystal structure and crystallinity
of TiO2 did not change by the milling with electric discharge. On the other hand,
noticeable absorption in Vis light range was observed, suggesting nitrogen doping into
the powder.
363
Authors: Chung Hsin Lu, Jen Hsien Huang, Hsieh Hsin Chen, Po Hsiung Huang
Abstract: TiO2 sol with steady suspension and high photocatalytic activity was prepared via a
precipitation-peptization method. The XRD results indicate that the TiO2 sol exhibited an anatase
structure. TiO2 films on woven fabrics (carbon, PET and Nylon), prepared via dip-coating with TiO2
sol, were characterized by XRD and SEM analysis. The dependence of the woven fabrics properties
on the amount of TiO2 coated and photocatalytic activity were also studied. When the diameter of
fibers is smalle, large quantity of TiO2 is coated on woven fabrics leading to an improvement in the
photocatalytic activity. It is observed that the photocatalytic activity of TiO2 film coated on woven
fabrics exceeds that of TiO2 film coated on common glass substrate with the same surface area.
569
Authors: Soo Wohn Lee, Huang Chen, Yi Zeng, Chuan Xian Ding
Abstract: Nanostructured and conventional Al2O3, ZrO2, and TiO2 were deposited using an
atmospheric plasma spraying (APS). The size of commercial nano-ceramic powders was varied
from 5nm up to 150nm. The microstructure and phase composition of the plasma sprayed coatings
on metallic substrate were characterized by X-ray diffraction (XRD), scanning electron microscopy
(SEM), and transmission electron microscopy (TEM). It was found that nano-sized ceramic
powders enhanced the deposition efficiency on the metallic substrate rather than the micro-sized
conventional commercial powders. Density and mechanical property such as microhardness were
better in the case of the nano-sized ceramic powders than that of the conventional micro-sized
ceramic powders, which are associated with the fine surface roughness and less size in pores of the
coating layers. The wear rate of the nanostructured coating was lower than that of the conventional
coating. The results were explained in terms of their microstructure of the coatings layers. Also,
photocatalytic characterization of the plasma sprayed coatings, using nanocrystalline size TiO2 as
feedstock with various powder sizes and shapes as well as adding with different photocatalytic
oxides, was performed. The photocatalytic reactivity using plasma sprayed coating layers can be
utilized into various applications.
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