J. Phys. II France
Volume 7, Numéro 2, February 1997
Page(s) 295 - 304
DOI: 10.1051/jp2:1997126
J. Phys. II France 7 (1997) 295-304

Phase Separation in Polymer Solutions Induced by Shear

Akira Onuki, Ryoichi Yamamoto and Takashi Taniguchi

Department of Physics, Kyoto University, Kyoto 606-01, Japan

(Received 19 August 1996, received in final form 21 October 1996, accepted 5 November 1996)

We numerically investigate nonlinear regimes of shear-induced phase separation in entangled polymer solutions. Use is made of a time-dependent Ginzburg-Landau model describing two fluid dynamics of polymer and solvent. As a new dynamic variable a conformation tensor is introduced to represent chain deformations. Above the coexistence curve a dynamical steady states is attained, where fluctuations are enhanced on various spatial scales. At relatively large shear elongated polymer-rich regions form a transient network supporting most of the stress. Because such a network is continuously deformed in shear flow, the shear stress and the normal stress difference exhibit large fluctuations.

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