90 research outputs found
Influence of the nanostructure on the surface and bulk physical properties of materials
Fullerenes, nanotubes, quantum dots have been considered as effective sensitizers to modify both the spectral, optical, nonlinear optical features, dynamic and polarization characteristics, as well as mechanical properties of the organic and inorganic materials. Laser, spectroscopy, mass-spectroscopy, nuclear magnetic resonance methods have been apply to support the change in the physical properties of the new nanocomposites. The extending of the nanocomposites applications area has been considered
Features of the nanostructured materials for nonlinear optics and solar energy applications
The nonlinear refraction and third order susceptibility are discussed for different organic materials doped with fullerenes, shungites, carbon nanotubes, carbon nanofibers, quantum dots, etc. nanoobjects. The evidence of the correlation between laser induced change of the refractive index and charge carrier mobility are obtained. The features of new nanocomposites for their possible optoelectronics, laser techniques and solar energy applications are considered. The results have been supported by RFBR grant #10-03-00916
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
Spectral and mechanical properties of the materials structured with carbon nanotubes
Carbon nanotubes are considered as the good candidate to modify the surface properties of the organic and inorganic structures. Both the spectral and mechanical properties as well as quantum chemical simulation are discussed to explain the increase in transmission and hardness of the nanostructured polyvinyl alcohol films, magnesium fluoride, etc. The basic features of carbon nanotubes are regarded to their small refractive index, strong hardness of C⎯C bonds as well as complicated and unique mechanisms of charge carrier moving. The structures of the composite films and their mechanical properties are modeled too. The peculiarities of new nanostructured materials and their possible optoelectronics and display applications will be under consideration. The results have been supported by RFBR grant #10-03-00916 and RAS Presidium Program # 21
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
Accelerated optical solitons in reorientational media with transverse invariance and longitudinally modulated birefringence
We demonstrate that reorientational spatial solitons can curve when propagating in a medium with engineered walk-off along the direction of propagation. In this regard, we employ nematic liquid crystals with molecular anchoring defined by electron-beam lithography and optic axis distribution modulated in the longitudinal direction only, keeping the transverse orientation constant. The experimental results are in remarkably good agreement with a simple modulation theory based on momentum conservation
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