Phenomenological theory of textured mesophase polymers in weak flows

✍ Scribed by Alejandro D. Rey

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 726 KB
• Volume: 5
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/mats.1996.040050506

✦ Synopsis

Abstract

A macroscopic viscoelastic model for incompressible, isothermal, homogeneous lyotropic mesophases exhibiting the nematic polydomain texture is presented. Under equilibrium static conditions the model describes a three dimensional tessellation, where each region or nematic domain has a characteristic size and orientation, and where the polydomain texture has a random orientation. Close form expressions that define the characteristic texture size and the number of randomly oriented domains are given. When subjecting the model lyotropic liquid crystalline polymer displaying the polydomain texture to a steady rectilinear shear flow, the predicted characteristic texture size decreases with increasing shear rates. The power law scaling relations of texture size with shear rate are in excellent agreement with the experimental measurements. The steady shear flow orientation predictions, characterized by a positive shear dependent alignment angle and a low orientation, are in agreement with experimental data.