Measurement of nematic liquid crystal splay elastic constants by disclination line motion in high pretilt, negative dielectric anisotropy pi-cells

Negative dielectric anisotropy nematic liquid crystals confined to high pretilt pi-cells undergo a discontinuous, disclination mediated transition between a splayed and a twisted director configuration. A critical voltage, U-s, exists at which the two states are in equilibrium and hence the movement of disclination lines ceases. We show that measurement of U-s provides a simple and convenient means to determine the splay elastic constant, K11, of the liquid crystal to an accuracy of 10% or better. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767778]