Concentration dependences of dielectric properties at 105Hz and 106Hz for aqueous solutions of hydroxypropyl cellulose

The concentration dependences of dielectric properties measured at 10⁵ Hz and 10⁶ Hz are reported for aqueous solutions of hydroxypropyl cellulose. Phase behaviour of the solutions was also observed with a polarizing optical microscope. For solutions with concentrations well above 40 wt %, polydomain textures, including the banded texture, were observed after a prehistory of deformation. No significant discontinuous changes in the dielectric constant, ε_r', and loss factor, ε_r', were found at the concentrations around the onset of the isotropic-cholesteric phase transition and in the biphasic region. In contrast, the steeper changes in ε_r' and ε_r' were found at the critical concentration for the fully developed cholesteric phase transition with the polydomain textures.