Spontaneous emergence of chirality in achiral lyotropic chromonic liquid crystals confined to cylinders.
The presumed ground state of a nematic fluid confined in a cylindrical geometry with planar anchoring corresponds to that of an axial configuration, wherein the director, free of deformations, is along the long axis of the cylinder. However, upon confinement of lyotropic chromonic liquid crystals in cylindrical geometries, here we uncover a surprising ground state corresponding to a doubly twisted director configuration. The stability of this ground state, which involves significant director deformations, can be rationalized by the saddle-splay contribution to the free energy. We show that sufficient anisotropy in the elastic constants drives the transition from a deformation-free ground state to a doubly twisted structure, and results in spontaneous symmetry breaking with equal probability for either handedness. Enabled by the twist angle measurements of the spontaneous twist, we determine the saddle-splay elastic constant for chromonic liquid crystals for the first time.
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Karthik
K
Nayani
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Rui
R
Chang
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Jinxin
J
Fu
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Perry W
PW
Ellis
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Alberto
A
Fernandez-Nieves
1] School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2] Center for Advanced Research in Optical Microscopy, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Jung Ok
JO
Park
1] School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2] School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [3] Center for Advanced Research in Optical Microscopy, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Mohan
M
Srinivasarao