Advances in the metal nanoparticles (MNPs) doped liquid crystals and polymer dispersed liquid crystal (PDLC) composites and their applications - a review

Concentration-dependent dielectric and electro-optical properties of composites based on nematic liquid crystals and CdS:Mn quantum dots

“…16a represents the concentration dependence of U th . It has already been noted by many authors that the introduction of both metallic and semiconductor nanoparticles leads to a decrease in the threshold voltage 18,61 due to the adsorption of impurity ions by quantum dots and a decrease in their shielding effect. 62 The same phenomenon was observed in the ZhK-1289 and CdS:Mn (Mn 6%) composites.…”

Nanocomposites Based on Antiferroelectric Liquid Crystal (S)-MHPOBC Doping with Au Nanoparticles

“…The larger scattering is due to the bigger cross-section. According to Ahmad et al Au nanoparticles can take colors in the range of orange, red, brown, etc., depending on the core size, and usually show an absorption band in the range of 500-550 nm [86]. The smaller nanoparticles have an absorption maximum of around 520 nm, the larger ones scatter more and the shape of the absorption band is widened with the maximum shifted towards the red light.…”

“…After aggregation, the conduction electrons near the surface of each nanoparticle are delocalized and divided (shared) by the nearest nanoparticles which change the optical properties by shifting the surface plasmon resonance to lower energies (red shift). Therefore, non-aggregated Au nanoparticles absorb blue light while Au aggregated nanoparticles leads to significant shifts in the frequency of plasmon resonance towards red, broadening the absorption band and changing the solution color [86]. The simulated absorption spectra for Au nanoparticles (20-100 nm) in water turned out that for larger the diameter of nanoparticles, the absorption maximum shifts towards red light and the absorption efficiency initially increases with the size up to diameters equal to 70 nm, and then begins to decrease (radiation scattering begins to dominate over absorption) [87].…”

Advanced liquid crystal-based switchable optical devices for light protection applications: principles and strategies

“… where V is the applied electric field, while d, R, K, ω, ε 0 , Δ ε, l , and γ represent the film gap, droplet radius of the LC, elastic constant, aspect ratio, vacuum dielectric constant, dielectric anisotropy, shape anisotropy, and rotational viscosity constant, respectively. The addition of NPs changed the refractive index of the dielectric, the dielectric constant, and the anchoring properties of the liquid crystal, and thus, effectively improved the electro-optical properties of LC/polymer materials 130 , 137 . For example, SO 2 NPs changed the anchoring energy at the LC-polymer interface, and inorganic NPs such as ZnO and MgO changed the dielectric constant of the dielectric, both of which effectively reduced the driving voltage.…”