Nanostructured, electroactive and bioapplicable materials

To analyze and interpret data, most of the porosity characterization methods adapt
structural model assumptions and mathematical approximations. As a result, sometimes
they may not be able to reveal the real pore structure of porous materials. Based on image
analysis, 65 microscopic observation provides a straightforward evaluation of pore size,
shape and distribution. 66,67 The major advantage of microscopic characterization is that a
pore model is not necessary. The method allows a direct observation of the pore
structures. To ensure statistically representative results, sufficient samples must be
analyzed with this method.
Each of these analytical methods has its own advantages as well as suitable
working conditions. In general, the selection of the approaches should be dependent upon
the properties and the microstructures of the material under investigation. For the same
reason, it is normally insufficient for a single method to qualify for a confirmative
analysis of pore parameters. Therefore multiple analyses should be carried out to
facilitate a comprehensive understanding of the porosity. In our studies, the major
approaches used to study the porosity of mesoporous sol-gel silica are gas adsorption
measurement, small angle X-ray scattering and electron microscopy image analysis. Due
to its relative complexity and its considerable usage in our experiments, a brief discussion
on gas adsorption measurement is provided next as a subsection.
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