Investigating the Dielectric and Electro-Optical Characteristics of Gold Nanoparticles Dispersed in the Room Temperature 5CB Nematic Liquid Crystalline Display Material via Experimental Research

Abstract

Since the early 1990s, research on how nanomaterials affect the characteristics of liquid crystals has garnered significant attention from the scientific community. The nano size makes it possible to combine two entirely unrelated fields of study into the novel, cross-disciplinary field of soft matter and nanostructure. N-(biphenyl-4-yl)acetamide on reaction with n-pentoylchloride in presence of aluminum chloride gives N-(4¢-pentanoyliphenyl-4yl)acetamide, when treated with N₂H₄ and KOH affords 1-(4¢-aminophenyl-4-yl)pentan-1-one. This on further reaction with NaNO₂ and HCl at 0-5° C gives diazotized product 4¢pentylbiphenyl-4-diazoniumchloride. This product on working through Sandmeyer reaction affords 4¢-pentylbiphenyl-4-carbonitrile which is also recognized as 4¢-pentyl-4-cyanobiphenyl (5CB). This material is in a liquid crystalline form. Further, this material 5CB have been characterized and confirmed by various spectroscopic methods viz. ¹H-NMR and ¹³C-NMR. Furthermore, low dimensional templates i.e. AuNPs were doped in the synthesized liquid crystalline material i.e. 5CB. Additionally, we reported on an electro-optical and electrical research of gold nanoparticles (AuNPs) doped in nematic medium of synthetic liquid crystal 5CB at a single strength of 0.1 weight percent. Since it was discovered that AuNPs were bundled at higher concentrations in different locations, higher concentrations were not tested. Electrical (dielectric) spectroscopy was used to quantify the various electrical properties, such as dielectric permittivity, loss, relaxation frequency, dielectric anisotropy, and ionic conductivity for homeotropic and planar aligned samples in the 1 Hz–35 MHz frequency range. AuNPs might align from side to side to the nematic direction because of the nematic phase. Conversely, the local orientational organization of molecules in the nematic phase is enhanced by the presence of AuNPs. As a result, the threshold voltage needed to transition a molecular arrangement from a bright state, or planar arrangement, to a dark state, or homeotropic arrangement, is significantly lowered when AuNPs are present.