Texture characterization of ultramacroporous materials using non-destructive methods

Image analysis, impedance spectroscopy and X-ray microtomography have been used as non-destructive methods in order to characterize ultramacroporous materials (pore width > 1 mum). These methods are used to investigate the texture of different kinds of materials, i.e., highly oriented polylactide (PLA) foams prepared by freeze-drying, isotropic polyolefin foams prepared by thermal degradation of a chemical foaming agent and convective heat dried wastewater sludges. The image analysis of SEM micrographs recorded at different magnifications gave information on the pore size distribution and pore morphology. Impedance spectroscopy was used to investigate the transport properties of the three-dimensional porous matrices by measurement of the water ionic conduction. Finally, 3D image reconstruction from 2D cross-sections obtained by X-ray microtomography allowed visualizing the pore structure.