Effect of Surface Composition on Powder Flow Properties
The quantification of the major factors that affect powder kinematics is a challenge because of the surface composition heterogeneity of granular materials. Computational modeling and analytical studies lack an adequate representation of bulk cohesion on dry cohesive systems because they disregard the influence of high magnitude intermolecular interactions. The aim of this study was to understand the mechanism that drives changes in molecular dynamics on dry cohesive powders by evaluating the effect of chemical components at particle contact. Silica beads with varied particle sizes were coated with chemical structures that mimic the intermolecular interactions of surface components present in food-powdered products. Particle size and shape distributions, dynamic flow properties, shear flow properties and compressibility profile of the bulk systems were analyzed and the experiments validated using powders of analogous surface composition to that of surface modified silica beads. A correlation between the contribution of dispersive interactions and increased electron donor ability on powder flow hindrance helped to improve the understanding of the role of molecular level anisotropy on bulk cohesion. The findings of this study will collaborate to the development of robust quality control measures for handling and storage of powders and bulk granular systems in food, feed, and pharmaceutical applications.^
Rose Prabin Kingsly Ambrose, Purdue University.
Off-Campus Purdue Users:
To access this dissertation, please log in to our