X-ray structural modeling of silicate mesoporous mesophase material

Rietveld's technique in combination with a continuous electron density repr esentation was applied to structural modeling of highly ordered pure silice ous mesoporous mesophase material C16-SiO2-MMM of the MCM-41 type prepared by hydrothermal synthesis in the presence of C16H33N(CH3)(3)BR. Several imp ortant characteristics of the material in both as-synthesized and calcined forms were revealed. In particular, it was found that mesopores in the mate rials are of true hexagonal shape, and the wall electron density seems to b e not continuous. (C) 2001 Elsevier Science B.V. All rights reserved.