Fabrication and Characterization of Single Phase α-Alumina Membranes with Tunable Pore Diameters

Materials

Sachiko Ono¹  Hidetaka Asoh¹  Tatsuya Masuda¹  Satoshi Haraguchi² 

[1] Graduate School of Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan;Toshiba Corporation Power and Industrial Systems Research and Development Center, 1 Toshiba, Fuchu, Tokyo 183-8511, Japan;

关键词: anodizing;    porous anodic alumina film;    membrane;    crystallization;    α-Al2O3;    filtration property;   

DOI  :  10.3390/ma8031350

来源: DOAJ

【 摘 要 】

Nanoporous and single phase α-alumina membranes with pore diameters tunable over a wide range of approximately 60–350 nm were successfully fabricated by optimizing the conditions for anodizing, subsequent detachment, and heat treatment. The pore diameter increased and the cell diameter shrunk upon crystallization to α-alumina by approximately 20% and 3%, respectively, in accordance with the 23% volume shrinkage resulting from the change in density associated with the transformation from the amorphous state to α-alumina. Nevertheless, flat α-alumina membranes, each with a diameter of 25 mm and a thickness of 50 μm, were obtained without thermal deformation. The α-alumina membranes exhibited high chemical resistance in various concentrated acidic and alkaline solutions as well as when exposed to high temperature steam under pressure. The Young’s modulus and hardness of the single phase α-alumina membranes formed by heat treatment at 1250 °C were notably decreased compared to the corresponding amorphous membranes, presumably because of the nodular crystallite structure of the cell walls and the substantial increase in porosity. Furthermore, when used for filtration, the α-alumina membrane exhibited a level of flux higher than that of the commercial ceramic membrane.

【 授权许可】

Unknown