Mechanism for flow-rate controlled breakup in confined geometries: a route to monodisperse emulsions.
This Letter describes a quasistationary breakup of an immiscible, inviscid fluid at low capillary numbers. The breakup proceeds in a coflowing, viscous liquid, in a confined geometry of a long and narrow orifice. In contrast to the capillary instability in an unbounded fluid, the collapse proceeds through a series of equilibria, each yielding the minimum interfacial energy of the fluid-fluid interface. The process is slow in comparison to typical relaxation speeds of the interface, and it is reversible. Its quasistatic character of collapse forms the basis for controlled, high-throughput generation of monodisperse fluid dispersions.
Garstecki
Piotr
P
Chemistry and Chemical Biology Department, Harvard University, 12 Oxford Street, Cambridge, Massachusetts, USA. pgarstecki@gmwgroup.harvard.edu
Stone
Howard A
HA
Whitesides
George M
GM