SPring-8, the large synchrotron radiation facility

Date&Time: 16:00 - 17:00, 12 October 2004

Speaker: Prof. Osamu Terasaki
Affiliation: Structural Chemistry, Arrhenius Laboratory, Stockholm University, Sweden

Abstract
　　Many three dimensional (3d-) silica mesoporous crystals have been synthesised with the help of self-organisation mechanism of amphiphilic molecules. Through removal of the molecules, we can use in principle the crystals as rigid templates/moulds for making a variety of nano-structured materials within the pores.
　　In order to use mesoporous crystals for various applications, it is essential to know (i) 3d-structure of the crystals, which is regular arrangement of cavities surrounded by amorphous silica, and (ii) the accessibility of the internal pores from the external surface. We have developed a method to solve 3d-structure, that is 3d-electrostatic potential distribution, of silica mesoporous crystals by electron crystallography (EC) and succeeded in solving some of their silica-structures [1]. We have also succeeded in observing directly the accessibility by SEM image[2].
　　At my talk, I will discuss a role of electron microscopy (TEM and SEM) for the study and will show some of 3d-structures of (i) mesoporous crystals[1, 3], (ii) nano-materials with characteristic structural features[4], and (iii) the latest progress including chiral mesoporous crystals[6].

References:
[1] A. Carlsson et al. J. Electron Microscopy 1999,48,795, Y. Sakamoto et al. Nature 2000, 408,449.
[2] S. Che et al. Angew. Chem. Int Ed., 2003, 42, 2182.
[3] A.E. Garcia-Bennett et al. Chem Mater. 2004, 16, 813-821.
[4] R. Ryoo et al. J.Phys.Chem. 1999,B103,7743, O. Terasaki et al. Microsc. Microanal., 2002, 8, 35.
[5] S. Che et al. Nature 2004, 429, 281-284.