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

Silica mesoporous materials have attracted a lot of attention in different field ranging from chemistry, to engineering or even pharmacy since the first mesoporous material were reported in early 1990's. Mesoporous materials have two main structural characteristics: disorder on atomic scale (short-range), but well-defined order on mesoscopic scale (long-range). Their features rise in poor resolved X-ray diffraction patterns with little structural information. On the other hand, transmission electron microscopy (TEM) has been a very powerful tool to characterize the structure with mesoscale order. We have developed a method based on electron crystallography that gives an electrostatic potential distribution of the three dimensional (3D) mesoporous structures. Based on the 3D electrostatic potential distribution, direct information of the detailed structures inside the mesoporous materials such as diameter, shape and connectivity of the pores can be obtained.

Here we show our recent results performed in Stockholm. The main topics are (i) structural characterization of new mesoporous materials, AMS-8 (space group Fd-3m), AMS-9 (P4₂/mnm), and AMS-10 (Pn-3m), using TEM with electron crystallography, and future work concerning 3D reconstruction, (ii) some other examples of TEM studies for mesoporous materials, e.g. multiply twined particle of mesoporous material, polymer replica of mesoporous material with two dimensional hexagonal structure, and drug delivery system using mesoporous materials, (iii) analytical approach to determine the pore shape and size of MCM-41 using XRD data, (iv) structural characterization of zeolite Ti-YNU-1 using XRD and TEM.