Drop Dynamics in Complex Fluids

James J. Feng, Xiaopeng Chen, Pengtao Yue & Chunfeng Zhou

Invited chapter in
Understanding Soft Condensed Matter via Modeling and Computations, Chapter 11, pp. 339-363
Vol. 3 in World Scientific series on "Soft Condensed Matter"

(November 2010)

Abstract - This chapter describes the unusual behavior of interfaces between complex fluids through two examples: the partial coalescence between a drop and a planar interface, and the interaction and self-assembly of droplets suspended in a nematic liquid crystal. The main message is that coupling among 3 disparate length scales — the microscopic scale of molecular and supramolecular configuration, the mesoscopic scale of the interfaces, and the macroscopic scale of hydrodynamics — produces interfacial dynamics that may differ markedly from that in Newtonian fluids. A diffuse-interface theory provides a convenient framework for describing two-phase complex fluids, and finite-element computations reproduce the main features of the experimental observations, and reveal the underlying physical mechanisms.