Stereological macropore analysis of a controlled pore glass by use of small-angle scattering

A first measurement (1) of the isotropic Small-Angle Scattering intensity I(h) of a defined controlled mesoporous glass before and a second measurement (2) after alkaline removing of the mesoporous colloidal silica in the macropores of the main silica framework were performed. Consequently, (1) considered a mesoporous glass (MePG) and (2) considered the immediately-afterwards-outcoming macroporous glass (MaPG). The SAS correlation functions and the chord-length distribution densities of the macropores were determined in both cases (so-called filled (1) empty (2) macropores). There exist no differences between outer size and shape and geometrical arrangement of filled/empty macropores at all. Certainly, as a consequence of the missing filling of the macropores in the MaPG-case, the scattering intensities are changed by a constant factor for small h-values and absolutely different for large h-values. The geometric arrangement of the macropores, distances 20 nm < r < 150 nm, involves a high symmetry in the corresponding MePG and MaPG type glass. There exists a relatively restricted placing of the pore axis and the pore positions in space.