This thesis demonstrates the first use of high-speed ultrasound imaging to non-invasively probe how the interior of a dense suspension responds to impact. Suspensions of small solid particles in a simple liquid can generate a rich set of dynamic phenomena that are of fundamental scientific interest because they do not conform to the typical behavior expected of either solids or liquids. Most remarkable is the highly counter-intuitive ability of concentrated suspensions to strongly thicken and even solidify when sheared or impacted. The understanding of the mechanism driving this solidification is, however, still limited, especially for the important transient stage while the response develops as a function of time. In this thesis, high-speed ultrasound imaging is introduced to track, for the first time, the transition from the flowing to the solidified state and directly observe the shock-like shear fronts that accompany this transition. A model is developed that agrees quantitatively with the experimental measurements. The combination of imaging techniques, experimental design, and modeling in this thesis represents a major breakthrough for the understanding of the dynamic response of dense suspensions, with important implications for a wide range of applications ranging from the handling of slurries to additive manufacturing.

An essential text on practical application, theory and simulation, written by an international coalition of experts in the field and edited by the authors of Colloidal Suspension Rheology. This up-to-date work builds upon the prior work as a valuable guide to formulation and processing, as well as fundamental rheology of colloidal suspensions. Thematically, theory and simulation are connected to industrial application by consideration of colloidal interactions, particle properties, and suspension microstructure. Important classes of model suspensions including gels, glasses and soft particles are covered so as to develop a deeper understanding of industrial systems ranging from carbon black slurries, paints and coatings, asphalt, cement, and mine tailings, to natural suspensions such as biocolloids, protein solutions, and blood. Systematically presenting the established facts in this multidisciplinary field, this book is the perfect aid for academic researchers, graduate students, and industrial practitioners alike.

Secondly, the stability and rheology of the single walled carbon nanotube (SWNT) suspensions prepared by interfacial trapping method is examined and compared to a conventional method of ultracentrifugation. Since the rheological properties are sensitive to the suspension microstructure, the change of rheological properties, such as viscosity, can be employed as a systematic standard of stability. The steady shear viscosities have been measured and compared as a function of shear rate and aging time of the suspension. Also, the visual states of the suspension have been observed. The rheology of the SWNT suspensions depends on the preparation of surfactant solution. Also, the interfacial trapping method generated similar behaviors to the SWNT suspension prepared by the ultracentrifugation method. Finally, the dynamics of non-colloidal spheres in oscillatory shear flow is studied by experiment and simulation. Two distinct scales are observed for the development of the rheology in time. At small total strains, a rapid decay of ... is observed, while ... and ... remain constant. However, the evolution of the complex viscosity is observed over large total strains, indicating microstructural changes over long times. Also, this suspension system shows a non-monotonic dependence of viscosity on strain amplitude. Stokesian dynamics simulations are used to correlate the rheology and microstructures.

This book is dedicated to the tube flow of viscoelastic fluids and Newtonian single and multi-phase particle-laden fluids. This succinct volume collects the most recent analytical developments and experimental findings, in particular in predicting the secondary field, highlighting the historical developments which led to the progress made. This book brings a fresh and unique perspective and covers and interprets efforts to model laminar flow of viscoelastic fluids in tubes and laminar and turbulent flow of single and multi-phase particle-laden flow of linear fluids in the light of the latest findings.