Rheological investigations on cholesterol derivative mesogens

The rheological investigations on cholesteryl bromide (CB) and cholesteryl 2-(ethoxy-ethoxy) ethyl carbonate (CEEEC) were carried out. The viscoelastic properties of both mesogens are strongly temperature dependent. In CB, the temperature scans on moduli discovered an abrupt change which is an indication of Smectic phase. In frequency sweep, the CEEEC is characterized by a prevalent viscous behavior while for CB a cross-over of moduli with dominating storage modulus. A shear thinning followed by Newtonian flow is found in CB and Newtonian flowin CEEEC. This study infers the usefulness as lubricants and additive in triboloy.