Dynamics and flow-induced phase separation in polymeric fluids

TL;DR

This paper reviews recent advances in understanding the dynamics of polymeric fluids, including theories, phase behavior, and flow-induced transitions, highlighting complex behaviors in systems like wormlike micelles.

Contribution

It synthesizes recent theoretical and experimental developments in flow-induced phase separation and complex flow behaviors in polymeric fluids.

Findings

Improved reptation and molecular theories for polymer dynamics

Mapping of phase diagrams for flow-induced transitions in micelles

Identification of complex shear-thinning and shear-thickening behaviors

Abstract

The past few years have seen many advances in our understanding of the dynamics of polymeric fluids. These include improvements on the successful reptation theory; an emerging molecular theory of semiflexible chain dynamics; and an understanding of how to calculate and classify ``phase diagrams'' for flow-induced transitions. Experimentalists have begun mapping out the phase behavior of wormlike micelles, a ``living'' polymeric system, in flow: these systems undergo transitions into shear-thinning or shear-thickening phases, whose variety is remarkably rich and poorly understood. Polymeric ideas must be extended to include the delicate charge and composition effects which conspire to stabilize the micelles and are strongly influenced by flow.