日本ゼオライト学会　刊行物 Publication of Japan Zeolite Association

Increasing attention has been focused on mesoporous materials such as MCM-41, because of their great applicability as catalysts, molecular sieves and host materices, based on their large internal surface areas and narrow pore size distributions. The synthesis of porous alumina templated by surfactant assemblies has been approached by the alkoxide method as well as the homogeneous precipitation method using urea. The former approach gives mesoporous alumina with specific surface areas of as high as 400-700 m²·g⁻¹, but with a disordered pore structure, in contrast to the long-range hexagonal arrangement of pores observed for the MCM-41 silica. The latter method, on the other hand, provides aluminium-based mesophases with layer and hexagonal structures templated by alkyl sulfates. The hexagonal surfactant mesophase occurs in versatile morphologies such as spherical, funneled, tubular and hexagonal-rod shapes. On calcination, the hexagonal mesophase is deorganized into a hexagonal but less ordered framework structure and finally converted into similar-shaped but macroporous particles of α-alumina. Co-incorporation of dodecyl sulfate and alkyl alcohol in the aluminiumbased systems results in the formation of a lamellar mesophase with biomimetic surface patterns such as cone-shaped or terraced hollows and domed-scales.