The resolution available in the King's College London scanning transmission x-ray microscope (STXM) can be exploited to study aggregate structures over a length scale from 100 nm to 10 micrometers that overlaps with and complements that available from small-angle x-ray scattering (SAXS) data. It is then possible to use these combined sets of data to test between different growth models for the aggregates, using the fractal dimension of the structures as a way of distinguishing the different models. In this paper we show some of the first transmission x-ray images taken of silica gels and zeolite precursors, materials that are of great practical and economic importance for certain selective catalytic processes in the chemical industry, and yet for which there is still only limited understanding of the complicated processes involved in their preparation. These images reveal clearly the fractal aggregates that are formed by the specimens.

Date Published: 13 January 1993
PDF: 4 pages
Proc. SPIE 1741, Soft X-Ray Microscopy, (13 January 1993); doi: 10.1117/12.138746

Published in SPIE Proceedings Vol. 1741:
Soft X-Ray Microscopy
Chris J. Jacobsen; James E. Trebes, Editor(s)