Accession Number:

AD0848719

Title:

Physical Properties of the Cholesteric Mesophase.

Descriptive Note:

Interim rept. no. 3, 10 May 67-10 May 68,

Corporate Author:

KENT STATE UNIV OH LIQUID CRYSTAL INST

Personal Author(s):

Report Date:

1968-06-26

Pagination or Media Count:

44.0

Abstract:

This report outlines research on the properties of ultrasonic waves 11 MHz, 14.5 MHz and 30 MHz in a cholesteric liquid crystal. The method involves the measurement of the complex reflection coefficient that occurs when a transverse mechanical wave reflects from the boundary of a fused quartz substrate and a liquid crystal. Another measurement involves phase-coherent detection as a means of measuring phase-shift using ultrasonic shear waves. The reflection coefficient is quite sensitive to the liquid crystalline state. There is a large change in the reflection coefficient r at the nematic-isotropic point but its dependence on temperature is not always the same at different frequencies. At some frequencies plots of r as a function of temperature show an increase in r as the temperature rises while at other frequencies r decreases. Phase-shift measurements in cholesteryl nonanoate show only a few degrees shift which is characteristic of most liquids. Values for skin depth and velocity of ultrasonic waves in cholesteryl nonanoate were established. Author

Subject Categories:

  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE