Dynamic light scattering studies on a lyotropic discotic nematic liquid crystal

Abstract

We have measured the twist viscoelastic coefficient of a lyotropic nematic liquid crystal composed of disc-like micelles of cesium perfluoro-octanoate (CSPFO) in water employing dynamic light scattering. We find that the twist viscoelastic coefficient increases with increase in temperature in the nematic phase. We have studied the viscoelastic response of the medium with the concentration of CSPFO in water. Twist viscoelastic coefficient rapidly increases with the concentration of CSPFO in water at a given reduced temperature. We have estimated the activation energy associated with the twist dynamics. We find that the activation energy is nearly independent of the concentration of CSPFO in water. We have also studied the effects of doping polyethylene glycol polymer on the viscoelasticity of CSPFO-water system.