Lee Ji-Hoon, Lim Tong-Kun, Yoon Tae-Hoon
School of Electrical Engineering, Pusan National University, Pusan, Korea.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 1):051705. doi: 10.1103/PhysRevE.83.051705. Epub 2011 May 16.
A cylindrical uniaxial liquid crystal was hydrogen-bonded with a tripod-shaped molecule. As the molecular number ratio of cylindrical liquid crystal to tripod molecule converges to 2:1, |s| = 1/2 disclination defects, which are a necessary condition of biaxial nematic phase, appeared predominantly. After the application of an electric field, the |s| = 1/2 disclinations converted to |s| = 1 disclinations which imply a transition from a biaxial to uniaxial state. IR dichroism measurements support the hypothesis that the liquid crystal-tripod molecule complex undergoes a molecular conformation change from bent shape to parallel shape, and this conformation change is thought to be related to a field-induced biaxial-uniaxial transition.