The Leslie coefficients and Frank parameters respectively characterize the viscosity and elasticity of these materials, whose (*) order parameter is given by the average of the second-order Legendre polynomial of the cosine of the angle between the molecular axis and the local director.
The expression for the free energy density of these materials includes a term that is typically calculated using the Rapini-Papoular approximation. Imura-Okano theory describes these materials' anomalous dispersion of ultrasonic waves. Kapustin-Williams domains appear in these materials when an applied voltage induces the Carr-Helfrich instability. The Leslie coefficients and Frank parameters respectively characterize the viscosity and elasticity of these materials, whose (*) order parameter is given by the average of the second-order Legendre polynomial of the cosine of the angle between the molecular axis and the local director. Distortions of the structure of these materials occur via bends, splays, and twists, the latter of which can be controlled using an electric field in order to change their opacity. For 10 points, name this class of materials whose thermotropic variety exhibits smectic and nematic phases, the latter of which is widely used in electronic displays.
The expression for the free energy density of these materials includes a term that is typically calculated using the Rapini-Papoular approximation.
liquid crystals [accept specific types]