IMPRINTING OF NEMATIC ORDER AT SURFACES CREATED BY POLYMERIZATION-INDUCED PHASE-SEPARATION

Surface interactions of liquid crystals at interfaces are crucial for the performance of devices that use liquid crystals. Many dispersions of polymers and liquid crystals for electro-optic applications are mad e by polymerization-induced phase separation into a nematic and a poly mer gel component. Imprinting of nematic order onto polymer interfaces created in this way was studied. Imprinting renders the interface ani sotropic so that the liquid crystal has a preferred In-plane orientati on. The interface can be imprinted with nematic order when the polymer network is formed but not after. Also, imprinting survives an excursi on through a temperature-driven anchoring transition. These observatio ns argue that imprinting is due not to surface-adsorbed. mesogens, but to an anisotropic arrangement of the polymer network at the interface . Surface imprinting affects electro-optic Properties of polymer-dispe rsed liquid crystal films in this study and it can be manipulated by a n external field during film formation.