Greta Cukrov 





Greta Cukrov  

Graduate Student
Chemical Physics Interdisciplinary Program

Tel.: 330-672-1520
 gcukrov@kent.edu 






             

Greta is investigating the temperature dependence of topological defects in the liquid crystal droplets exhibiting nematic (N) and underlying twist-bend nematic (Ntb) phases with a use of polarizing optical microscopy. In this study, two surface anchoring boundary conditions are adopted: 1) tangential (director n is parallel to the droplet’s surface) and 2) homeotropic (n is perpendicular to the droplet’s surface). In N phase of the studied material, the droplets with a tangential anchoring possess two point defects, boojums, of strength 1 at the poles, while the ones under a homeotropic condition show a point defect, hedgehog, of strength 1 at the center of the droplets. These defects are normal topological features in the nematic phase. As the temperature approaches the transition temperature, however, the hedgehog in the droplets with a homeotropic anchoring splits into two point defects. As T is lowered further, the split defects move toward the poles of the droplet and are eventually located at poles in the Ntb phase. The transition is ascribed to the significant drop of the bend elastic constant K3 near Nematic to Twist-Bend Nematic temperature. Further experiments are in progress to verify how the intriguing features of the elastic constant in the Ntb phase affect the director configuration and topological behavior in the droplets. She is also investigating the temperature dependence of the defects of the twist-bend nematic liquid crystal which is injected into a round capillary tube.

Click on the following links for his recent research and the list of the publications:

         

Curriculum Vitae