Determination of the anisotropic potential at the nematic liquid crystal-to-wall interface

The integrated birefringence of a surfactant (C16H33NH2)-aligned methoxybenzylidene butylaniline cell as a function of applied magnetic field (up to 100 kG) has been measured. The Oseen and Frank elastic continuum theory and a generalized torque balance equation at the interface have been utilized for the calculation to fit the measured data. A very good fit to the data was obtained using an anisotropic liquid crystal-to-wall interfacial potential of the form C cos2 θ+C4 cos4 θ for the calculation. It was found that C4/C=−0.38.