Influence of the Nanostructures on the Surface and Bulk Physical Properties of Materials

Fullerenes, nanotubes, quantum dots are considered as effective sensitizers to modify both the optical, nonlinear optical features, dynamic and polarization characteristics, as well as mechanical and spectral properties of the organic and inorganic materials. The correlation between photorefractivity and photoconductivity was supported and the relation between charge carrier mobility of pure conjugated structures and nanoobjects-doped ones has been revealed. An increase of transmission of nanostructured polarization films was observed. An extension of the nanocomposites applications area is considered

Functional Smart Dispersed Liquid Crystals for Nano- and Biophotonic Applications: Nanoparticles-Assisted Optical Bioimaging

Functional nematic liquid crystal structures doped with nano- and bioobjects have been investigated. The self-assembling features and the photorefractive parameters of the structured liquid crystals have been comparatively studied via microscopy and laser techniques. Fullerene, quantum dots, carbon nanotubes, DNA, and erythrocytes have been considered as the effective nano- and biosensitizers of the LC mesophase. The holographic recording technique based on four-wave mixing of the laser beams has been used to investigate the laser-induced change of the refractive index in the nano- and bioobjects-doped liquid crystal cells. The special accent has been given to novel nanostructured relief with vertically aligned carbon nanotubes at the interface: solid substrate-liquid crystal mesophase. It has been shown that this nanostructured relief influences the orienting ability of the liquid crystal molecules with good advantage. As a result, it provokes the orientation of the DNA. The modified functional liquid crystal materials have been proposed as the perspective systems for both the photonics and biology as well as the medical applications

Особенности функционирования жидкокристаллических ячеек с введенными наночастицами CoFe2O4

The first experimental results on the functioning of liquid crystal cells doped with CoFe2O4 nanoparticles are presented. Transmission spectra in the visible and near-infrared range, dynamic parameters of the Fredericks effect, refractive characteristics, as well as wetting angles of the mesophase sensitized surfaces have been obtained. The measured surfaces were the K8 Crown glass, the conductive ITO and the ITO treated with a surface electromagnetic wave. The experiment was performed in order to establish the prospect of using such reliefs as a novel liquid crystal composite orientator sensitized with CoFe2O4 nanoparticles. A color change of the liquid crystal matrix, its refractive coefficients alterations, and the variation of inclination angle of the sensitized liquid crystal droplets on the considered reliefs were established. The time reaction parameters and the medium relaxation parameters were measured. It was proposed that the liquid crystal composition is a kind of an immersion medium that preserves properties of the introduced nanoparticles, which expands their application scope in optoelectronics and biomedicine.В работе представлены результаты первых экспериментов по функционированию жидкокристаллических ячеек с введенными в мезофазу наночастицами CoFe2O4. Измерены спектры пропускания в видимом и ближнем ИК-диапазоне, динамические параметры по эффекту Фредерикса, рефрактивные характеристики, а также углы смачивания сенсибилизированной мезофазой поверхностей на основе стекла: Крон К8, проводящего покрытия ITO и ITO, обработанного поверхностной электромагнитной волной, – для перспективы использования такового рельефа в качестве ориентанта новой жидкокристаллической среды. Установлено изменение цвета жидкокристаллической матрицы, ее рефрактивных коэффициентов и угла наклона капель сенсибилизированного жидкого кристалла на рассмотренных рельефах; измерены временны́ е параметры реакции и релаксации среды. Предложено, что жидкокристаллическая композиция является своего рода иммерсионной средой, сохраняющей свойства введенных наночастиц, что расширяет области их применения в оптоэлектронике и биомедицине