Structural and Thermomechanical Investigation of Lyotropic Liquid Crystal Phases Doped with Monodisperse Microparticles

Abstract

We present a study of the structural and thermomechanical properties of lyotropic phase in the quasi ternary system made of Cetylpyridinium chloride (CPCl)/hexanol/salt water (0.9 % by mass) with and without cobalt microparticles. Phase transition temperatures of the structural sequence isotropic L 1/nematic calamitic Nc,/hexagonal H have been determined by differential scanning microcalorimetry. Temperature induced developable domains in hexagonal phase H and disclinations in calamitic nematic phase Nc were observed in crossed polar optical microscopy in confined geometry. A rheological study of calamitic nematic phase Nc highlighted structuring effect of cobalt microparticles from a concentration of 2 % to be demonstrated by an increase in viscosity and viscoelastic moduli. This could be explained by a stabilization of disclinations.

Keywords

• cement
• limestone
• rheology
• stabilising agent
• coarsely dispersed systems
• diutan gum
• starch ether