Shear induced order in phase separated polymer solutions
Summary
The behavior of phase separated polymer solutions under shear was studied by confocal microscopy in cone-plate and coaxial cylinder shear geometries. The observations were combined with macroscopic images, viscosity measurements and heterodyne light scattering velocity profiles. Wormlike banding, gradient banding and continuous phase inversion was observed for samples with a lower viscous dispersed phase at specific shear rates. Shear rates and strains were deduced to be heterogeneously distributed over banded samples as a function of the viscosity ratio between the separated phases. Shear strain and Laplace pressure seem to be the most important variables in determining the structure of a given system.