Nesprava V. Optical and structure properties of composites based on cyanobiphenyl and inorganic nanoparticles.

The dissertation deals with the investigation of the interface interaction in nanocomposites based on liquid crystal 5CB doped with organomodified alumosilicate nanoparticles (montmorillonite, MMT) or hybrid "organomodified montmorillonite (OMMT) - carbon nanotubes (CNT)" particles. A method to synthesize these hybrid nanoparticles has been created. CNT and OMMT interconnecting mechanism in hybrid particles had been determined. The structural organization and interface interaction peculiarities in the composites depending on MMT physico-chemical properties were studied. It has been established, that all interactions in composites originated from Van der Waals or Coulomb forces resulted in the composite morphology. In turn, these factors specify electro-optical (EO) and electroconductivity properties of such systems. It was determined that EO memory of LC composite depends on intermolecular interaction type between 5CB dimers and OMMT particles. CNT presence in the composites leads to light transmittance decrease and memory drop. Electroconductivity value and its temperature behavior for the 5CB based composites were determined to be significantly depended not only on the MMT geological origin but also on OMMT:CNT concentration ratio in the composite. These factors were found to influence the microstructure of composites, homogeneous distribution of filler particles and the possibility of percolation network formation determined the electro-physical properties of such systems. A phenomenological model of inorganic particles self-organization in the composites depending on OMMT:CNT concentration ratio is proposed.