Study on the Memory Effect in Aerosil-Filled Nematic Liquid Crystal Doped with Magnetic Nanoparticles.

A study on 5CB liquid crystal composites with SiO nanoparticles and an additional commixture with FeO nanoparticles using light transmission and SAW measurements is presented. The prepared liquid crystal composites exhibited an interesting memory effect characterized by the hysteresis of both light transmission and SAW attenuation responses investigated in the nematic phase. While in the case of SiO nanoparticles as dopants, the liquid crystal composite showed an improvement in the memory effect, the addition of FeO magnetic nanoparticles resulted in the memory effect decreasing.

Clustering in ferronematics-The effect of magnetic collective ordering.

Clustering of magnetic nanoparticles can dramatically change their collective magnetic properties, and it consequently may influence their performance in biomedical and technological applications. Owing to tailored surface modification of magnetic particles such composites represent stable systems. Here, we report ferronematic mixtures that contain anisotropic clusters of mesogen-hybridized cobalt ferrite nanoparticles dispersed in liquid crystal host studied by different experimental methods-magnetization measurements, small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), and capacitance measurements.

Orientational self-assembly of nanoparticles in nematic droplets.

We demonstrate experimentally that the anchoring of a nematic liquid crystal on a solid substrate together with the anchoring of the liquid crystal on a nanoparticle surface induces orientational self-assembly of anisometric nanoparticles in liquid crystal droplets. The observed phenomenon opens a novel route for fabrication of thin colloidal films with tailored properties.