Abstract
Concentrated aqueous solutions of a triple helical polysaccharide schizophyllan with molecular weight 4 * 105 were investigated by polarizing microscopy and laser light diffraction at 30[ddot]C. The solutions were birefringent above a polymer weight fraction w of about 0.098, indicating the formation of a liquid crystalline phase. This liquid crystalline phase resembled in many respects cholesteric mesophases reported for polypeptide liquid crystals, and was found to be also cholesteric. It was characterized by a cholesteric pitch of the order of several μm varying approximately in proportion to w −1.9. The system studied was completely liquid crystalline above w = 0.127 but biphasic in the range of w between 0.098 and 0.127, and underwent an isotropic-liquid crystalline phase transition when the temperature was changed.