SEM investigations of the polymer morphology in the liquid crystal-polymer composites with different polymer contents

Scanning electron microscopy was employed to study the evolution of the morphology of liquid crystal -polymer composites with increasing contents of a polymer. The composites were formed by a nematic mixture E7 from Merck and a photocurable adhesive NOA65 from Norland by means of photoseparation. The polymer phase reveals a smooth transition from a polymer network to a sponge-like structure and then to the `Swiss cheese' morphology with the increasing fraction of a polymer. It is established that the best electro-optic performance is demonstrated by samples with the well-developed sponge-like structure of the polymer phase.