Determination of compaction and surface in mesostructured materials using SAXS

An experimental method to determine simultaneously the compaction and the total specific area between an inorganic oxide network and a material of low electronic density (organic surfactant or air) is presented. This method is applicable when both the Porod limit and the invariant can be extracted from the small-angle X-ray scattering pattern on an absolute scale. An example is given using a hybrid precipitate of zirconium oxide and a cationic surfactant (CTAB). In such a mesostructured material, the total measured interface and the geometrically modelled one differ by a factor of 4, while compaction is about 0.4, well below 1. This is attributed to the presence of microporosity, in addition to the mesoporosity. The validity of the method is demonstrated using goethite as a reference inorganic material of known compaction equal to 1.