Shear oscillation light scattering of droplet deformation and reconfiguration in concentrated emulsionsJ.-R. Huang1, 2 and T. G. Mason1, 2, 3
1 Department of Physics and Astronomy, University California-Los Angeles - Los Angeles, CA 90095, USA
2 Department of Chemistry and Biochemistry, University of California-Los Angeles - Los Angeles, CA 90095, USA
3 California NanoSystems Institute, University of California-Los Angeles - Los Angeles, CA 90095, USA
received 28 April 2008; accepted in final form 30 May 2008; published July 2008
published online 3 July 2008
Large strain-amplitude oscillatory shear flows can cause significant structural changes in concentrated suspensions of deformable colloidal spheres that have volume fractions exceeding the quiescent jamming limit of hard solid spheres. In contrast to hard spheres, which can jam, lock-up, and even break fixed-gap shearing devices, droplets can readily deform and remain lubricated. By introducing shear oscillation light scattering, we explore how shear-induced droplet deformation facilitates un-jamming, ordering, disordering, and re-jamming of uniform concentrated droplets as a function of the amplitude, frequency, and phase of an applied oscillatory shear.
82.70.Kj - Emulsions and suspensions.
83.60.Rs - Shear rate-dependent structure (shear thinning and shear thickening).
83.80.Iz - Emulsions and foams.
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