title: Capillary breakup of discontinuously rate thickening suspensions.
abstract: 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.
authors.affiliation: Department of Mechanical Engineering, Hatsopoulos Microfluids Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. pzimoch@mit.edu
authors.forename: Pawel J
authors.initials: PJ
authors.lastname: Zimoch
authors.forename: Gareth H
authors.initials: GH
authors.lastname: McKinley
authors.forename: A E
authors.initials: AE
authors.lastname: Hosoi
mesh_terms: D003314:Corn Oil / Q000737:chemistry; D008962:Models, Theoretical; D011092:Polyethylene Glycols / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D013535:Suspensions / Q000737:chemistry*; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D011137:Polystyrenes; D013535:Suspensions; D014867:Water; D011092:Polyethylene Glycols; D003314:Corn Oil