Liquid Crystalline Nanomaterials Extracted from Egg Yolk: Encapsulation and Characterization of Their Electro-Optical Activity as Potential Materials for Flexible LCD Displays

Abstract

Cholesteric liquid crystal (CLC) compound present in egg yolk is extracted and characterized by polarized optical microscope, differential scanning calorimetry, scanning electron microscopy, dynamic light scattering and electro-optical measurements, confirming its potential use as an active material in the fields such as flexible liquid crystal displays. Emulsion polymerization is used to fabricate a flexible polyurethane shell with different thicknesses over CLC nanoparticles. Finally, thin films of prepared core–shell nanoparticles and poly(vinyl alcohol) as the binder are fabricated on the indium tin oxide substrates via knife-coating method and their electro-optical properties are evaluated. The films responded to applied potentials (4–18 V) by a 46–100% change in transmittance levels. The high shell thickness (5–45 nm) caused the need for higher voltages, because of the difficulty in feeling of the external field by liquid crystal (LC) core through the polymer shell. In the case of very thin or no polymer shell, the LC core becomes damaged or deformed under the electric field.