Nanocolloids comprising harvested ferroelectric LiNbO₃ nanoparticles (≈25 nm) and ferroelectric liquid crystals were prepared and investigated. The impact of the amount of dispersed nanoparticles (0.01 wt%, 0.05 wt%, 0.10 wt%) on the electro-optical, dielectric and material parameters of the ferroelectric liquid crystals (FLCs) has been demonstrated. The dopant strongly influences the switching characteristics and has an effect on the saturation voltage of the FLC materials. Electro-optical measurements demonstrated that a relatively large (0.10 wt%) LiNbO₃ dopant concentration decreases the response time and saturation voltage by approximately 40% and 25% respectively, compared with non-doped FLCs. The effect of LiNbO₃ nanoparticle concentration on the material and dynamical parameters (i.e. spontaneous polarization, dielectric permittivity, dielectric absorption, dielectric strength, dc conductivity, and rotational viscosity) is presented. The observed behaviours are discussed in terms of capture of impurity ions on the surface of the harvested LiNbO₃ nanoparticles. Ion capturing leads to enhancement of the localized electric field inside the smectic layers. The fast switching response and the low operational voltage of these FLC nanocolloids support their application in nanometric scale electronic devices.

The influence of the size of harvested barium titanate nanoparticles on the properties of ferroelectric liquid crystal (FLC) nanocolloids was investigated by electro-optical and dielectric methods. The spontaneous polarization and the switching time are decreased for the liquid crystalline nanocolloids compared to nondoped FLC mixtures of different dipole strengths; this dependence is stronger for small size particles (9 nm) and weaker for larger size particles (26 nm) by the same concentration in weight. The decrease of the Goldstone mode (GM) relaxation frequency and the decrease of the dielectric GM absorption strength of the nanocomposites compared to the nondoped FLC mixture go stepwise with the increase of the nanoparticles diameter. Results have been interpreted via strong interaction between the FLC dipoles and the dipoles of the highly polar barium titanate nanoparticles.

The influence of gold nanoparticles dispersed in ferroelectric liquid crystals (FLCs) on the properties of the resulting nanocolloids has been investigated by thermoanalytical, electrooptical and dielectric methods. All gold nanoparticles were protected by thiolate capping layers either connected via alkyl groups of different chain length or via flexible spacers bridged to liquid crystalline p-cyano-biphenyl end groups. The colloidal stability of the gold nanocomposites with capping layers consisting of nonyl or octadecylthiolate groups is drastically reduced compared to the stability of those with p-cyano-biphenyl end groups. The present work describes the influence of the kind of capping layers around the gold nanoparticles and the effect of the amount of gold nanoparticles dispersed in such liquid crystal colloids on their electrooptical and dielectric parameters.

Dispersion of the C-dots in n -hexane under ambient light and under 366 nm illumination indicating the bright photoluminescence of the C-dots; PL spectra of C-dots at different excitation wavelengths (360 nm to 540 nm) increasing at 20 nm intervals.