Polymer Chains under Strong Flows: Stems and Flowers

Authors: F. BROCHARD-WYART, A. BUGUIN

Abstract: We review here the unwinding of one tethered polymer chain, swollen or ideal, immersed: {\it i)} in a pure solvent, {\it ii)} in a polymer solution. Under a constant flow velocity V, a flexible polymer (in a steady state) is expected to display three types of conformation: 1) unperturbed at low V; 2) ``trumpet": partly stretched, with certain scaling laws, at intermediate V; 3) ``stem and flower" with a completely stretched portion (the stem) at high V. We also consider transients where (starting from regime 3) the flow is abruptly supressed and the resulting decay law for the stem is of the Rouse type.

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