Capillary Breakup of Discontinuously Rate Thickening Suspensions

TitleCapillary Breakup of Discontinuously Rate Thickening Suspensions
Publication TypeJournal Article
Year of Publication2013
AuthorsZimoch P.J, McKinley G.H, Hosoi A.E
JournalPhysical Review Letters
Start Page036001

Using discontinuously rate thickening suspensions (DRTS) as a model system, we show that beads-on-a-string morphologies can arise as a result of external viscous drag acting during capillary-driven breakup of a non-Newtonian fluid. To minimize the perturbative effect of gravity, we developed a new experimental test platform in which the filament is supported in a horizontal position at the surface of an immiscible oil bath. We show that the evolution of thin DRTS filaments during the capillary thinning process is well described by a set of one-dimensional slender filament equations. The strongly rate-dependent rheology of the test fluid and the aspect ratio of the filament couple to control the thinning dynamics and lead to a simple criterion describing the localized arrest of the capillary thinning process and the subsequent formation of complex, high aspect ratio beads-on-a-string structures.