Textures of Methyl Cellulose/Dichloroacetic Acid Mesomorphic Solutions

Abstract

Textures of methyl cellulose/dichloroacetic acid mesomorphic solution were studied by polarizing microscope and small angle light scattering. It was found that the mesomorphic solution showed the characteristics of cholesteric liquid crystals and the mesophase texture was closely related with the concentration. The mesomorphic solution showed the disk-like texture when mesophase appeared at first. After the mesophase became a continuous phase, however, there were observed the band-like texture and the pseudoisotropic texture in the solution. With the further increasing of concentration, the band-like texture was gradually destroyed and the pseudoisotropic texture changed to focal-conic structure. In the disk-like texture and the band-like texture, the axes of helicoids in cholesteric phase were parallel to the solution plane. In the pseudoisotropic texture they were perpendicular to it. The pitch of cholesteric mesophase decreased with changing from the disk-like texture to the band-like texture.