A viscometric study of the liquid crystalline phase of alkyloxybenzoic acids

The viscosities of three benzoic acid derivatives (p-n-heptyloxy-, p-n-decyloxy-, and p-n-dodecyloxy-) were measured on a unique viscometer of the class of CS-rheometer-viscometers with controlled shear stress over the whole temperature range of the liquid crystalline state. Shear rates were calculated and flow and viscosity curves constructed from the experimental shear stress values taking into account the Rabinovich-Moony correction. The smectic and nematic phases were characterized by non-Newton and Newton viscosities, respectively, in all the samples studied. The activation parameters of viscous flow were calculated for Newton viscosity. The results are discussed in terms of intermolecular interactions and structural peculiarities of liquid crystalline phases. © 2009 Pleiades Publishing, Ltd

Rheology of liquid crystalline phases of alkyloxybenzylidene toluidines

A unique viscometer of the CS rheometer viscometer class designed at the Kazan State University of Technology is used to measure viscosities of two p-n-alkyloxybenzylidene-p-toluidines in the entire temperature range of the liquid crystalline state and transition into an isotropic liquid. The measured shear stresses and flow rates are used to calculate shear rates and plot flow and viscosity curves. The liquid crystalline phase and isotropic liquid are demonstrated to possess Newtonian viscosity, whose viscous flow activation parameters are calculated in the temperature range under study. The results are discussed from the standpoint of intermolecular interactions and structural details of the liquid crystalline phase. © 2010 Pleiades Publishing, Ltd

A viscometric study of the liquid crystalline phase of alkyloxybenzoic acids

The viscosities of three benzoic acid derivatives (p-n-heptyloxy-, p-n-decyloxy-, and p-n-dodecyloxy-) were measured on a unique viscometer of the class of CS-rheometer-viscometers with controlled shear stress over the whole temperature range of the liquid crystalline state. Shear rates were calculated and flow and viscosity curves constructed from the experimental shear stress values taking into account the Rabinovich-Moony correction. The smectic and nematic phases were characterized by non-Newton and Newton viscosities, respectively, in all the samples studied. The activation parameters of viscous flow were calculated for Newton viscosity. The results are discussed in terms of intermolecular interactions and structural peculiarities of liquid crystalline phases. © 2009 Pleiades Publishing, Ltd