Tunable dynamic fragility and elasticity in dense suspensions of many-arm-star polymer colloids
Department of Materials Science and Frederick Seitz Materials Research Laboratory, University of Illinois 1304 West Green Street, Urbana, IL 61801, USA
Corresponding author: email@example.com
Accepted: 8 June 2010
A microscopic theoretical study of glassy dynamics in dense fluids of soft many-arm-star polymers is performed which elucidates the connection between local packing, shear elasticity and activated relaxation. A soft-jamming crossover is identified, below which particle-softness–dependent apparent power law concentration scaling of the shear modulus and supra-exponential relaxation occur. Dynamic fragility varies over a remarkably wide range, increasing logarithmically with star functionality. Beyond the soft-jamming threshold, the shear modulus increases linearly with volume fraction.
PACS: 64.70.pv – Colloids / 64.70.Q- – Theory and modeling of the glass transition
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