Stereo-Tem Imaging of Sol-Gel Glass Surfaces

Abstract

ABSTRACTSol-gel top and cross-fractured surfaces have been Pt-C replicated (9.7–11.3 Å thick) and carbon film backed (100–145 Å thick) and separated from the gel with an HF solution. Samples made from both base catalyzed LUDOX/Kasil mixtures and acid catalyzed alkoxides were studied with tilt series of 104 to 105 magnification TEM mlcrographs of the surface replicas. The LUDOX/Kasil gels contained spherical particles with a raspberry-like morphology and the acid catalyzed alkoxIdes are composed of densely packed filaments and no apparent particles. The smallest structural entity in both gels are Pt/C coated filaments (12–14Å) estimated to be 1.5–2.7 Å in width. The pore sizes were characterized in both gel types, though TEM pore measurements were only made on the LUDOX/Kasil gels.