Dr. Jun-ichi Fukuda: Formation of a zigzag defect structure in a liquid crystal confined within a microwrinkle groove

Formation of a zigzag defect structure in a liquid crystal confined within a microwrinkle groove

Dr. Jun-ichi Fukuda, National Institute of  Advanced Industrial Science and Technology (AIST), Japan

We show that, when a nematic liquid crystal is confined in a microwrinkle
groove of sinusoidal form, it exhibits a line defect of orientational order
(disclination line) of a zigzag form, instead of a straight one that can be
imagined intuitively. This is attributed to the hybrid anchoring conditions
(normal anchoring at the liquid crystal/air interface, and fixed planar
anchoring perpendicular to the groove direction at the groove surface), and
the preference for twist distortions over splay and bend distortions in
usual nematic liquid crystals of rod-like form. We will also discuss the
transformation of this zigzag line defect due to temperature change, and the
relation of the topological charge of the defect and the sign of the
curvature of the groove.

(Note: Experiments were carried out by Takuya Ohzono)

References:
T. Ohzono and J. Fukuda, Nature Communications 3, 701 (2012)
T. Ohzono and J. Fukuda, Soft Matter 8, 11552 (2012)
T. Ohzono, J. Fukuda, K. Suzuki and T. Yamaguchi, Phys. Rev. E 86, 030701(R) (2012).

Predavanje bo v ponedeljek, 10. februarja 2014 ob 13.15 v Seminarski sobi fizike (Soba 106) na IJS, Glavna stavba, Jamova cesta 39, Ljubljana.