Reconfigurable multi-compartment emulsion drops formed by nematic liquid crystals and immiscible perfluorocarbon oils

Liquid crystalline (LC) oils offer the basis of stimuli-responsive emulsions. Whereas past studies have explored the properties of single-phase LC emulsions, few studies have focused on complex multi-compartment emulsions containing coexisting isotropic and LC domains. In this paper, we report a study of multiphase emulsions using LCs and immiscible perfluoroalkanes. We found that the nematogen 4′-pentyl-4-biphenylcarbonitrile (5CB) anchors homeotropically (perpendicularly) and weakly at perfluorononane (F9) interfaces, consistent with smectic-layering of 5CB molecules. The proposed role of smectic layering is supported by experiments performed with 4-(trans-4-pentylcyclohexyl) benzonitrile (PCH5), a nematogen that possesses a cyclohexyl group that frustrates smectic packing and leads to tilted orientations at the F9 interface. By employing fluorocarbon and hydrocarbon surfactants in combination with multiphase 5CB and F9 emulsion droplets dispersed in a continuous glycerol phase, we observe a range of em...