 |
Center for Nonlinear Studies |
The microstructure of soft materials (such as emulsions, suspensions, and macromolecular solutions) can be significantly affected by an external flow. Flow can deform individual suspended particles (e.g., drops or macromolecules) and influence interparticle correlations. Flow-induced microstructural changes determine macroscopic properties of soft materials (e.g., mechanical and optical properties). I will discuss two important microhydrodynamic mechanisms governing microstructural evolution in dispersion flows. One of them is particle stabilization (against deformation) by the vorticity component of the external flow, and the other is the swapping-trajectory phenomenon that occurs in confined suspension flows. The first mechanism is responsible for drop bistability and a new coil-stretch transition in flexible macromolecules. The second mechanism brings about diverse hydrodynamic effects, e.g., suspension ordering and anomalous hydrodynamic diffusion. A deep understanding of microstructural evolution is vital for emerging technologies, for example for flow-guided fabrication of microstructured materials. Our results elucidate hydrodynamic mechanisms underlying such applications.
Host: Robert Ecke