The internal structure of a particle is an important attribute that determines macroscopic properties such as bulk density, effective mechanical properties, or dissolution rate. In this review article, the experimental and computational methods for the analysis of particle structure are summarized. After a critical review of the advantages and limitations of instrumental methods for two- and three-dimensional structure visualization, such as SEM and x-ray microtomography, several computational algorithms for the evaluation of quantitative descriptors from digital structure images are introduced. The idea of structure “fingerprint”, i.e. a set of numerical values uniquely defining the structure, is proposed. Finally, the complete powder structure characterization methodology is demonstrated on two application examples. The key conclusion of this review is that a wide portfolio of experimental and computational methods for structure characterization exists and is ready for practical use. However, at present our ability to quantitatively characterize particle structure exceeds our understanding of the relationships between processing, structure and end-use application properties of particles, which should be the focus of further research.
Keywords: microstructure, image analysis, integral characteristics, porous media, product design.