Formation mechanisms of macropore-like structure filled with micropores （skeleton structure）and conventional macroporous structure （macropores being not filled with micropores）are studied. By controlling the current density and HF concentration in the electrolyte solu tion, it has been clarified that the skeleton structure is formed under conditions where the bulk HF concentration is higher and the current density is lower. Porous silicon prepared under such conditions does not have oxidized silicon at the bottom of pores. This suggests that the mechanism of the skeleton structure formation is totally different from that reported for the explanation of conventional macropore formation. In this study we propose a model for skeleton formation based on hole-supply in a silicon electrode.
When Kalcolor membranes were calcined at 300 ℃, the color changed from black-brown to brown. At temperatures higher than 750 ℃, the color became white. To ascertain the cause of the color change, the membranes were analyzed using EDX. Decreasing concentrations of carbon and sulfur in the membranes were observed during calcination. Carbon was not detected when calcined at temperatures higher than 750 ℃. Therefore, the cause of the membrane coloring is inferred as carbon.
Cationic methylene blue（MB＋）dye was adsorbed onto a positively charged anodic porous alumina（APA）surface using sodium dodecyl sulfate（SDS）aqueous solutions. We conducted MB＋ adsorption by dipping APA in MB＋/SDS solutions（method 1）and by two successive dippings of APA in SDS solutions and MB＋ solutions（method 2）. The two methods produced different adsorption characteristics.
The electrical connection between dispersed conductive polymer particles is an important factor for reducing equivalent series resistance. Results show that the solvent's electric susceptibility dominates the formation of electrical connections among the conductive polymer particles.
The structures and properties of plasma electrolytic oxidation（PEO）coatings in alkaline electrolyte on titanium and titanium alloy Ti6Al4V were investigated. A dark gray anodic coating with 1-3 μm thickness, the same as that described in the AMS 2488 standard, was obtained using PEO followed by mechanical post-treatment. It has been shown that the anodic coating exhibits excellent adhesion, a low friction coefficient, and enhanced wear resistance. After PEO and post-treatment, no substrate strength decrease or measurable change in dimensions was observed.