BAND TEXTURES IN THE PRESHEARED HYDROXYPROPYLCELLULOSE FILM AND CORRESPONDING EVOLUTION PROCESS

The band textures in the presheared hydroxypropylcellulose (HPC) aqueo us solution, a typical lyotropic polymeric liquid crystal, are studied experimentally, and the corresponding real-time evolution is detected with time-resolved polarized optical microscopy (POM) and small-angle laser scattering (SALS). The maximum divergence angle of the local di rector relative to the preshearing direction increases with time. A no vel morphology, the bamboo-like band texture is found after cessation of shear flow. The bands are wavy in the intermediate stage of the rel axation process. The transition from a highly-oriented mono-domain to multiple domains is revealed from both POM and SALS observations. The evolution process of the presheared HPC solution is roughly divided in to three stages.