title: Collective Rayleigh-Plateau Instability: A Mimic of Droplet Breakup in High Internal Phase Emulsion.
abstract: Using a microfluidic multi-inlet coflow system, we show the Rayleigh-Plateau instability of adjacent, closely spaced fluid threads to be collective. Although droplet size distributions and breakup frequencies are unaffected by cooperativity when fluid threads are identical, breakup frequencies and wavelengths between mismatched fluid threads become locked due to this collective instability. Locking narrows the size distribution of drops that are produced from dissimilar threads, and thus the polydispersity of the emulsion. These observations motivate a hypothesized two-step mechanism for high internal phase emulsification, wherein coarse emulsion drops are elongated into close-packed fluid threads, which break into smaller droplets via a collective Rayleigh Plateau instability. Our results suggest that these elongated fluid threads break cooperatively, whereupon wavelength-locking reduces the ultimate droplet polydispersity of high-internal phase emulsions, consistent with experimental observations.
authors.affiliation: Department of Chemical Engineering, University of California , Santa Barbara, California 93106-5080, United States.
authors.forename: Vincent
authors.initials: V
authors.lastname: Mansard
authors.affiliation: Formulation Science, Core Research and Development, The Dow Chemical Company , Midland, Michigan 48674, United States.
authors.forename: Jodi M
authors.initials: JM
authors.lastname: Mecca
authors.affiliation: Formulation Science, Core Research and Development, The Dow Chemical Company , Midland, Michigan 48674, United States.
authors.forename: Dan L
authors.initials: DL
authors.lastname: Dermody
authors.affiliation: Formulation Science, Core Research and Development, The Dow Chemical Company , Midland, Michigan 48674, United States.
authors.forename: David
authors.initials: D
authors.lastname: Malotky
authors.affiliation: Formulation Science, Core Research and Development, The Dow Chemical Company , Midland, Michigan 48674, United States.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Tucker
authors.affiliation: Department of Chemical Engineering, University of California , Santa Barbara, California 93106-5080, United States.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Squires