Conoscopic observation of director reorientation during Poiseuille flow of a nematic liquid crystal

Director reorientation under pressure driven (Poiseuille) flow is observed conoscopically for the liquid crystal 5CB aligned at an azimuthal angle of 45 degrees to the direction of flow. A polyimide surface treatment (AL 1254) is used to promote planar homogeneous alignment and rubbed to produce an initial azimuthal alignment angle phi(0). Conoscopic interference figure rotation is documented as a function of flow rate and compared to that produced from numerical models using Leslie-Ericksen-Parodi theory. Model and data show excellent agreement. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3251792]