Band formation in HPC solutions by consecutive shearing along orthogonal directions

Experiments of banded texture formation in lyotropic HPC aqueous solutions are reported. A parallel plate apparatus is used, which allows for consecutive shears along mutually orthogonal directions. In the double shear experiment, the effects of the following variables have been explored: first and second deformation shear units, shear rate of the second movement, delay time between the two deformations. The results show that the formation of a banded texture oriented orthogonally to the first shear is strongly enhanced by introducing the second shear motion. The mechanisms of formation of the texture are discussed.