Lyotropic Liquid Crystalline Structures of Synthetic Polypeptide 2. Measurements of Elastic Constants and Coupling Constants of Poly(γ-Benzyl L-Glutamate) Solutions by the Freedericksz Transition

Abstract

The object of this report is the determination of material parameters of the lyotropic polymer liquid crystal, poly(γ-benzyl L-glutamate)-1,1,2-trichloroethane solutions, by means of the Freedericksz transition with the magnetic field. The critical field strength Hc of the homeotropic polymer liquid crystal was determined in the condition without hysteresis. The bend elastic constant K33=1.3-1.0×10-11 N and the coupling constant B=4.4×10-6 J m-2 (weight fraction of polymer, w2=0.173 and 0.138) were obtained from the relations between Hc and the cell thickness. The splay elastic constant K11=1.6×10-11 N (w2=0.173 and 0.138) was obtained by the simulations of the transition curves. The ratio K11/K33 exceeds one and is larger than those of the small molecular liquid crystal.