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The applications of liquid crystals in the field of renewable, clean and sustainable technologies of energy storage are of utmost importance at present. This paper delves into dielectric spectroscopic studies of a weakly polar nematic liquid crystal (NLC) enriched with an anthraquinone dye. The primary objective is to assess the impact of increasing dye concentrations on various properties. Anthraquinone dye has been found to increase the dielectric permittivity of weakly polar NLC, leading to a 4.7-fold increase in dielectric anisotropy. Simultaneously, a reduction of around 11% in threshold and operating voltages of the NLC has also been recorded after using dye as the guest material. The added dipolar contributions provided by dye molecules have been attributed to this surplus permittivity. The NLC has been found to have an approximately 54% faster response to the applied field. The intrinsic polarization field of dye molecules accelerates nearby LC molecule reorientation, leading to a 56.5% faster fall time and a 29.8% faster rise time in a 3.0 wt% dye-doped LC cell. These experimental results have been validated via computational studies as well. The simulation results about dipole moment and polarizability provide robust support for our experimental results. Such composites evince their potential for energy storage and 5G communication technologies with adjustable impedance and permittivity. [ABSTRACT FROM AUTHOR]

The present investigation on the impact of porous carbon nanoparticles (PCNPs) on a room temperature nematic liquid crystalline compound (TP‐188‐01) reports extensive electro‐optical analysis of composite followed by dielectric and luminescence study as well. The pure nematic compound has been doped with 0.1%, 0.25%, and 0.5% of PCNPs (spherical), which have been synthesized by green synthesis technique without use of any activating agents. Low‐frequency dielectric analysis (50 Hz to 1 kHz) has been done to confirm ion generation with increase in PCNS concentration. The dielectric data also indicate preferential orientation of molecules from homogeneous to homeotropic alignment, which can be used in performance optimization of electro‐optical devices. The analysis of dielectric data also illustrates the application of PCNS‐doped systems in circuits operating at high voltages. Diffusion coefficient, mobility, and DC conductivity have been further examined to support the above observations. A significant decrease (of about 47%) in the response time of porous carbon nanoparticle liquid crystal (NP‐LC) composites has also been observed. The photoluminescence spectrum of NP‐LC composites as a function of carbon nanosphere (CNS) concentration has shown Quenching (following the Stern–Volmer quenching mechanism) in the luminescence intensity with increasing CNS concentration. The highly improved response time and quenching in the luminescence intensity further make the PCNS‐doped LC composites as ideal materials to be used in devices, encouraging LC‐aided green nanotechnology. [ABSTRACT FROM AUTHOR]

In present work, Cu:ZnO nanoparticles (NPs) used to disperse in pure nematic liquid crystal N-(4-methoxybenzylidene)-4-butylaniline (MBBA). Due to their larger dipole moment of NPs have stronger interactions with the liquid crystal molecules which lead to enhance the ordering of the nematic molecules as demonstrated by the increase in the value of mean dielectric permittivity. The dispersion of Cu:ZnO NPs on the dielectric behavior and activation energies as a function of temperature and frequency has studied for various concentrations of Cu:ZnO NPs. The complex dielectric permittivity and the relaxation frequency are dependent on the concentration of Cu:ZnO NPs. Theoretically obtained activation energy and relaxation times (Slater's perturbation equations) have been found in good agreement with experimental results. An effort has been made to explain these results on the basis of interaction between nematic molecules and NPs. [ABSTRACT FROM AUTHOR]

The effect of biowaste porous carbon nanoparticles (PCNPs) on the dielectric and electro-optical properties of nematic liquid crystal (LC) mixture (1823A) of 4-(4-alkyl-cyclohexyl) benzene isothiocyanates and 4-(4-alkyl-cyclohexyl) biphenyl isothiocyanates has been studied. The dielectric permittivity of nematic LC has been increased with the dispersion of carbon NPs. The dielectric anisotropy has been calculated and found to be decreased with the dispersion of PCNPs into the pure nematic LC. The response time and birefringence have been also observed with the variation of temperature, frequency as well as the concentrations of carbon NPs. After the dispersion of PCNPs achieved better birefringence and faster response in the dispersed system, which is the significant application in display devices. Threshold voltage splay elastic coefficient and rotational viscosity have been calculated for both pure and NPs dispersed nematic system. Its value is increased with the dispersion of NPs. Additionally, photoluminescence and figure of merit have investigated as a comparative study of nematic matrix as well the dispersed system. The experimental results have been found to have good agreement with the theoretical data of nematic LC. An effort has been made to explain these experimental results on the basis of interaction between nematic molecules and carbon NPs. [ABSTRACT FROM AUTHOR]

Dielectric and electro-optic properties of a weakly polar nematic liquid crystals (NLCs) based on polyvinyl pyrrolidone capped gold nanoparticles doping has been reported. The dielectric spectra of these composites with a concentration of 0.25 wt%, 0.5 wt%, and 1.0 wt% are recorded in the frequency range of 42 Hz to 5.5 MHz. Dielectric permittivity and dielectric loss in these samples have been analyzed for both homogeneously-aligned and vertically-aligned liquid crystal (LC) cells. It has been observed that GNPs doping significantly reduce the threshold voltage (~27%) for LC reorientation which is explained by increased dielectric anisotropy and decreased splay elastic constant of doping LC cells. Nearly 57% faster fall time is also observed as a consequence of a remarkable reduction in the relaxation time (about short molecular axis) thus rotational viscosity of the doping LC cells. GNPs doping has an auspicious application to the fields of LC devices and displays. The present work shows that the composite under investigation performs far better than the pure LC cell in the display as well as photonic applications. • The color performance was also observed but slightly decreased transmission. • Threshold voltage of the LC cells decreased by 27% for 1 wt% doping concentration. • 57% faster response time of nematic LC is achieved. • Birefringence of the LC mixture also decreased by ~23%. • Orientational order parameter of the LC mixture also decreased by ~23%. [ABSTRACT FROM AUTHOR]