Dielectric and Light-Scattering Features of a Pseudopeptide-Polymer-Integrated Nematic Liquid Crystal with Negative Dielectric Anisotropy

Abstract

We present the dielectric and light-scattering properties of a liquid crystal (LC) with negative dielectric anisotropy that has been incorporated with an amino acid-based pseudopeptide polymer. The polymer precipitates in the form of micrometer-sized spheres in the negative dielectric anisotropy nematic liquid crystal (nLC), which serves as a nonsolvent. Ion density, diffusion coefficient, conductivity, and ion mobility are investigated from experimental dielectric measurement of the nLC, which contained pseudopeptide polymer at concentrations of 2.5, 5, and 7.5 wt %. The polymer’s incorporation into a nLC enhances the ion density, diffusion coefficient, conductivity, and ion mobility. The change in the ionic properties has a major impact on the electrohydrodynamic instability (EHDI) of the LC. The incident light is scattered by the chaotic turbulence state produced by the EHDI effect. The light-scattering characteristics of the polymer-stabilized LC are investigated by using direct transmission. The pseudopeptide polymer microsphere in the nLC significantly enhances the light-scattering performance. The stated method demonstrates the fabrication of a light-scattering device utilizing LCs and a polymer without employing UV or thermal curing processes. The nLC with the polymer significantly enhances the light scattering in the EHDI state, provides a high contrast ratio, and significantly lowers the voltage needed to generate the scattering state. The light-scattering characteristics of the device can be utilized in various electro-optic systems that rely on light scattering, such as projection displays, smart windows, and tunable light diffusers.