Smectic A – Cholesteric Phase Transition: A Viscosity Study

Abstract

Viscosity measurements of the cholesteryl myristate as a function of temperature and shear rate are presented. Ranging from the smectic A phase to the isotropic phase the data cover every liquid crystalline interval of the compound. It is shown that the viscosity values of the sample, originated from the non-fixed director alignment, can be reduced to a unique temperature dependent curve. That is, using a simple scaling hypothesis, it is shown that curves corresponding to the different shear rates coalesce into a single viscosity curve characterizing each different phase of the compound.

Rheological Theory and Simulation of Surfactant Nematic Liquid Crystals

“…Surfactant lyotropic liquid crystals are composed of self -assembled aggregates that display the multifunctionality associated with mesophases and fi nd industrial applications in drug delivery, lubrications, detergency, viscosifi ers, and turbulence suppression (Rey, 2010 ). Given the practical importance of fl ow and rheology, this chapter focuses on rheological modeling of surfactant nematic solutions emphasizing the connection between orientational order, fl ow kinematics, and order kinematics, reviewing recent works on surfactant liquid crystal (Alves et al, 2009 ;Erni et al, 2009 ;Fernandes and Figueiredo Neto, 1994 ;Fernandes et al, 2006 ;Kuzma et al, 1989 ;Lee, 2008 ;Palangana et al, 1990 ;Richtering, 2001 ;Sampaio et al, 2005 ;Simoes et al, 2000Simoes et al, , 2005Sonin 1987 ).…”