RESUMO
The influence of the surface nanostructured relief on the near IR-spectral shift and on the structural properties of the nematic liquid crystal (NLC) materials doped with nanoparticles from lanthanide group has been considered. The relief mentioned above has been made on the interface between glass substrate with ITO-coatings and the LC mesophase. The specific feature of this relief is based on the applying of the contactless laser deposition technique and on the its modification by using surface electromagnetic waves (SEW) or carbon nanotubes (CNTs) treated with SEW. The modified relief permits to orient LC molecules without direct polymer orienting layers and can be used as conducting layer too. The features mentioned above lead to decrease drastically the resistivity and the bias voltage as well as that permits to increase the transparency and reveal the near IR-shift in the spectral characteristics of the lanthanide-doped LC mesophase.
RESUMO
It has been shown that replacing of O-CH3 substituents in PVK-phenyl derivative chromophores by C-N groups leads to appearance of long-ranged dipole-dipole interactions in the composites including PVK-CN, fullerenes and cyano-biphenyl derivatives. Following quantum chemical calculations it has been demonstrated that interaction of the chromophores with the LC matrices favors dipole-dipole ordering, however it description requires to take into account non-homogenous space charge density distribution. During doping by PVK-CN derivatives phase transition has been found from uniaxial system with pure nematic to the quasi-smectic LC state with the substantially different parameter of ordering. Moreover it was established that during this substitution the switching times drastically jump from millisecond to microsecond regime.
