On topological defects in polymer-dispersed liquid crystal films

The article is devoted to an experimental study of the morphology of nematic liquid crystals embedded in porous polymer matrices. We have discussed the principles of operating systems in which LCs demonstrate the effect of electromechanical memory, as well as the importance of interaction of topological defects with a porous medium. The study of the morphology of polymer-dispersed-liquid-crystal (PDLC) films has shown that at a ratio of LC: polyvinyl acetate = 1:1, the liquid is encapsulated in isolated cavities with an average size of 5 μm. With an increase in the proportion of LC in the matrix we observe the formation of interconnected structures on a scale of tens of microns, which leads to an increase in the concentration of point defects with a charge number of +1. We have concluded that this increase in the concentration of defects is a consequence of both an increase in the volume of the liquid crystal and a complication of the pore shape in the polymer matrix. The results emphasize the importance of understanding the morphology and behavior of topological charges in liquid crystal systems for the development of new materials with controlled optical properties.