Abstract
Starting from the Debye theory of rotational Brownian motion, we analyzed the dielectric relaxation phenomena with molecular orientational ordering in Langmüir film on a water surface, assuming that the orientational distribution of the constituent rodlike polar molecules is ruled by Boltzmann statistics. The transient behavior of the polar molecules induced by the application of step compression at the molecular area is discussed with taking account of the friction constant of monolayer , and the dielectric relaxation time . Here is the critical molecular area defined as (: the length of rodlike polar molecule). The orientational order parameter of monolayers and Maxwell displacement current (MDC) at the dielectric relaxation process were obtained, for the first time, with the consideration of and . On the basis of the analysis developed here, we examined the generation of MDC across 4-cyano-4′-5-alkyl-biphenyl (5CB) Langmüir film by monolayer compression.
- Received 17 June 1996
DOI:https://doi.org/10.1103/PhysRevE.54.6603
©1996 American Physical Society