Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>Experimental results on sorption-induced deformation during n-pentane
desorption were obtained by in-situ dilatometry and in-situ small
angle X-ray scattering (SAXS). The sample investigated was
a silica-based monolith with hierarchical pore structure comprising
a macroporous network of struts, each strut containing well-defined
cylindrical mesopores ordered on a 2D hexagonal lattice. In-situ
dilatometry and in-situ SAXS measurements revealed strain isotherms of
similar shape, which are qualitatively in good agreement with recent
theoretical predictions. From the relative pressure range of the
liquid filled mesopores a pore load modulus of 1.5 GPa is
determined. The relative pressure region of mono- and multilayer
formation, however, reveals differences between the two independent
methods. In particular, the net strain at saturation pressure is
considerably larger for in-situ dilatometry. We attribute this
observation to the different sensitivity of the two methods to
anisotropic deformation in the hierarchical solid framework. While
in-situ SAXS measures the mesopore lattice strain and is therefore
exclusively sensitive to radial deformation of the struts, dilatometry
measures the linear deformation of the isotropic macroscopic sample,
being sensitive to the volumetric strain of the whole network.</jats:p>