A laser beam micro surface finishing method attempted to remove hard anodic oxide film formed on aluminum specimens. The hardness of the film increases with increasing applied current density during anodizing and decreasing concentration of SO42− ions. Specimens were irradiated in solutions with a pulsed Nd-YAG laser beam through a convex lens with 60mm focal length to remove anodic oxide film locally. Thin anodic oxide film can be removed without cracks by one pulse of laser irradiation, but thick oxide films need several pulses of irradiation removed without cracks. Thick as grown hard anodic oxide film was removed leaving numerous cracks and the size of the removed area increased with irradiation time. However, dyed thick anodic oxide film was removed layerwise at low irradiation power without cracks, because the dyed oxide film absorbed laser energy. The size of removed area of the dyed film did not change with irradiation time.
Electroless Plated Ni-P/TiO2 composite films were deposited from an acidic solution or an alkaline solution containing photocatalytic TiO2 particles (P-25). The dispersion of particles in the films was investigated by cross-sectional observation with a transmission electron microscope. The particle content in the films increased with an increase of its amount in the solutions. The deposition rate of composite films was independent of the amount of TiO2 particles in the solutions(0˜100g dm−3). Photocurrent density of the films in 0.1M NaOH aqueous solution rose with particle content in the films.
Potentiostatic cathodic electrodeposition of CdTe compound on a gold-plated substrate was studied at 70ºC using new acidic aqueous electrolytic baths (pH3.0) containing citric acid. The composition of the deposits was controlled by changing the deposition potential, which depended on the concentrations of Te(IV) and citrate. The stoichiometric CdTe layers obtained were polycrystalline, having a uniform surface morphology without pinholes. In the presence of citrate ions, the solubility of tetravalent tellurium species in the citrate bath at pH3.0 was more than 10mM, which was about one or two orders higher than that in conventional acidic sulfate baths. The increase in the solubility will be accounted for by a complexation between Te(IV) and citrate ions, which has not been reported so far. A set of linear sweep cathodic voltammograms for Te(IV)-citrate baths suggested the presence of the complex.
A series of Cu-Mn-Ce/Al2O3 anodic alumina catalysts synthesized using the multi-impregnation method were employed to investigate the selective reduction of NO with C3H6 in the presence of excess O2. The presence of Cu additive greatly promoted the low-temperature de-NOx activity. A moderate loading of copper gave the most promising NOx conversion. In contrast, no promotional effect on low-temperature de-NOx activity was found when Mn was added to the alumina support. Although the Mn-supported catalyst exhibited a higher activity for the oxidation of NO to NO2, the addition of Mn to the Cu-Ce/Al2O3 catalyst had no positive effect on NOx reduction, due to the wasteful consumption of propene. The de-NOx activity of the Cu-Ce/Al2O3 catalyst was maintained at a relatively high level, even in the presence of excess SO2 (500 ppm) and H2O (10 vol%). Furthermore, the presence of SO2 was observed to greatly promote NOx reduction at 723 K.
Transparent gas barrier silica films were synthesized on poly(ethylene terephthalate) substrates by a low-temperature plasma-enhanced chemical vapor deposition method using an organosilane/oxygen mixture. The gas barrier performances of the films were significantly affected by their structures and chemical compositions. Structural defects, such as grain boundaries, pinholes and cracks, degraded the gas barrier performance, as well as chemical-compositional defects, such as loosely packed siloxane-networks and imperfect siloxane-networks, due to the termination of networks with impurities. An excellent gas barrier performance was attained with a silica film consisting of densely-packed and fully cross-linked siloxane-networks.