Image analysis, impedance spectroscopy and mercury porosimetry characterisation of freeze-drying porous materials

Image analysis and impedance spectroscopy have been used as potential tools for the characterization of the texture of ultramacroporous PLA foams prep ared by freeze-drying. It has been shown that these two techniques actually provide valuable information on the structure of this material. They are c omplementary to mercury porosimetry, which does not allow morphological det ails to be distinguished. Image analysis of SEM micrographs of transverse c ross-sections at two different magnifications gave information on both the macroporosity (1 mum < width < 10 mum) and ultramacroporosity (width > 10 m um). Impedance spectroscopy was used to investigate the transport propertie s of the three-dimensional porous matrices by measurement of ionic conducti on. (C) 2001 Elsevier Science B.V. All rights reserved.