Molecular aggregation and ultrasonic properties of hydroxypropyl-cellulose films

Abstract

Ultrasonic properties of hydroxypropyl-cellulose films showing various cholesteric colors were examined as a function of temperature. The variously cholesteric colored films was prepared by casting from water and organic solvents. Cholesteric pitch was controlled mainly by heating time. Decrease of cholesteric pitch in the colored films leads to the ultrasonic velocity increase and ultrasonic attenuation decrease. A comparison of ultrasonic properties between planner and normal direction to the film demonstrated that interactions of inter-layer are more intensive compared with those between cholesteric domains.