纳米颗粒-介电复合材料三阶光学非线性的研究进展

纳米颗粒-介电复合材料显示出优良的三阶非线性光学性能,是应用于未来全光器件的理想材料.其中,纳米颗粒的尺寸、浓度、组成和结构,基体的选择,测试方法中选用的激光波长和脉冲宽度等多种因素都对此类复合材料的三阶非线性光学性能有很大的影响,了解这些影响因素对材料的制备和应用具有重要的指导意义.在此基础上,研究指出核壳结构纳米颗粒-介电复合材料具有更加优异的三阶非线性光学性能,是目前的研究热点.     

半导体量子点/聚合物纳米复合材料研究进展

半导体量子点/聚合物纳米复合材料是在分子尺度上形成的先进光电功能材料,其综合了半导体和聚合物材料的各自优点,并呈现出独特的电学、光学和光电子学等特性.根据聚合物中掺杂纳米半导体量子点材料的种类不同,对半导体量子点/聚合物纳米复合材料的制备、分类、器件结构与特性和研究进展进行了概要评述,并展望了其发展趋势.     

一维硅锗纳米复合材料的制备及在场效应晶体管中的应用

一维硅锗纳米复合材料，主要包括硅锗纳米线异质结与纳米管，具有优异的电学、光学等性能，易与现代以硅为基础的微电子工业相兼容，所以在纳米器件等领域得到了广泛重视。总结了一维硅锗纳米复合材料的研究现状和相关的制备方法，重点评述了在纳米场效应晶体管中的应用，并对其研究前景做了展望。     

聚乙烯醇缩丁醛/纳米TiO2复合材料的制备及性能研究

制备了不同聚乙烯醇浓度的聚乙烯醇缩丁醛(PVB),利用偶联剂和超声波分散法对纳米TiO2进行了表面处理,用共混法制备了PVB/纳米TiO2复合材料.采用FT-IR、XRD、SEM等测试手段表征了复合材料的红外吸收性能、光学性能、结构和微观形貌,测试了复合材料的力学性能.结果表明:由于纳米TiO2粒子的加入,复合材料的韧性得到明显提高,其断裂伸长率为纯PVB的6～8倍左右,同时使PVB/TiO2纳米复合材料具有良好的紫外线屏蔽性能.该材料的制备方法简便、易于操作,具有一定的工业应用前景.     

聚合物基金属纳米复合材料的研究进展

综述了聚合物基金属纳米复合材料在组织结构方面的各种影响因素,以及国内外在光学、电磁学、催化和传感等多种性能方面的研究进展.     

有机-无机纳米复合材料的制备、性能及应用

综述了有机-无机纳米复合材料的最新发展,包括该类材料的制备方法、性能研究和应用前景.纳米复合技术主要有3种:溶胶-凝胶法、嵌入法和纳米微粒填充法.纳米复合材料的光学和磁学等性能可用Maxwell形态理论、层状结构理论和分形结构理论等来研究.这类材料已在力学、热学、电学、磁学、光学、宇航和生物仿生等领域表现出广阔的应用前景.     

纳米纤维素的光电子性能及器件应用综述

纳米纤维素是一种近年来发展迅猛的具有胶体活性的材料，它具有携带可控电荷基团、化学活性高、光学活性高、质量轻、价格低及环境友好等特点，正在快速占领导电材料、显示器、传感器、晶体管、射频器件、发电机、发光二极管等光电子器件及关键材料领域的重要地位。目前，纳米纤维素在光电子材料器件的应用依然存在不少挑战，且纳米纤维素的光电子性能及其器件也未见报道。诸多科学问题和技术难点包括如何从纤维素出发赋予该种光电子新材料性能（胶体颗粒维度、化学基团、亲水性）、如何满足光电子器件结构加工对材料性能的要求、如何明确材料物理化学性质与器件制备的关联机制等需要总结和讨论。本文简单介绍了具有代表性的几种纳米纤维素的制备和特性，着重介绍了纳米纤维素的光电子特性，如光学透过性、光学干涉、散射、液晶手性特性等，列举和讨论了纳米纤维素在太阳能电池基板、智能响应反射涂层、光纤等领域的应用和存在的问题。本文有助于建立纳米纤维素关于制备、微观形貌特征、胶体颗粒尺度效应、关键物化特性和光电子器件性能之间的逻辑关系，可确定构建纳米纤维素相关的新器件结构的设计准则和理论根据，还可为纳米纤维素在乳液、薄膜、模板材料、储能器、电极、纸电...     

纳米电缆材料的研究进展

纳米电缆材料因其独特的光学性能、电学性能、磁学性能及几何结构而成为当今纳米材料研究领域的热点和重点.介绍了纳米电缆的研究进展、纳米电缆的结构和制备技术的发展状况,详细阐述了电弧放电、化学气相沉积、毛细管虹吸等多种制备方法,并展望了纳米电缆的发展和应用前景,纳米电缆的研究对于以纳米材料为基础而构筑的微纳米器件有着重要的意义.     

纳米陶瓷与纳米陶瓷粉末

八十年代中期发展起来的纳米陶瓷,使材料的超塑性、强度大为提高,对材料的电学、热学、磁学、光学性质产生重要影响,为材料的利用开拓了一个崭新的领域,已成为材料科学研究的热点之一．本文对纳米陶瓷的烧结与性能、纳米陶瓷粉体的制备及性能表征作了简要的综述．     

纳米Cu-Al2O3复合材料的烧结法制备研究

研究了纳米Al2O3陶瓷颗粒增强铜基复合材料制备技术.选用纳米级Al2O3陶瓷颗粒作为增强相,采用超声波增强化学镀的方法完成对纳米Al2O3陶瓷颗粒金属铜包覆,热压烧结成纳米Al2O3陶瓷颗粒增强铜基复合材料,开采用XRD、TEM等分析测试技术对其组织性能进行研究.     

Optical properties of polymer nanocomposites

Nanomaterials have emerged as an area of interest motivated by potential applications of these materials in light emitting diodes, solar cells, polarizers, light-stable colour filters, optical sensors, optical data communication and optical data storage. Nanomaterials are of particular interest as they combine the properties of two or more different materials with the possibility of possessing novel mechanical, electronic or chemical behaviour. Understanding and tuning such effects could lead to hybrid devices based on these nanocomposites with improved optical properties. We have prepared polymer nanocomposites of well-defined compositions and studied the optical properties of powders and their thin films. UV-vis absorption spectroscopy on nanocomposite powders and spectroscopic ellipsometry measurements on thin films was used to study the effect of interfacial morphology, interparticle spacing and finite size effects on optical properties of nanocomposites. Systematic shift in the imaginary part of the dielectric function can be seen with variation in size and fraction of the gold nanoparticle. The thickness of the film also plays a significant role in the tunability of the optical spectra.     

The Optical and Magneto-Optical Properties of Nanostructured Oxides of 3d-Metals

The electronic properties of nanostructured strongly correlated oxides CuO, Y₃Fe₅O₁₂, and FeBO₃ that include the fundamental absorption region, low-energy electron excitations, and phonon modes have been investigated by the methods of optical spectroscopy. Absorption and reflection spectra, Raman spectra, and ellipsometry measurements were on the samples of nanostructured ceramics carried out. High-density nanoceramics have been prepared by the shock-wave loading methods using high-pressure torsion from coarse-grain oxide powders. Strong diffusions of the fundamental absorption edge are revealed for all nanoceramics. Anomalous red shift of the absorption edge was observed in CuO nanooxide. The features of the optical functions in nanooxides of 3d-metals is found to be attributed to the high degree of imperfection of the nanooxides, peculiarities of the electronic structure of the strongly correlated oxides and inherent the electronic phase separation.     

High quality ZnO/CuO nanocomposites synthesized by microwave assisted reaction

Highly crystalline zinc oxide (ZnO) and ZnO/CuO nanocomposite powders have been synthesized by a facile microwave irradiation method. The resulting powders were characterized in terms of structural, optical and morphological properties by X-ray diffraction (XRD), room temperature photoluminescence (PL) spectroscopy and scanning electron microscopy (SEM), respectively. XRD patterns revealed the formation of ZnO/CuO nanocomposites with good crystalline quality. SEM images displayed the formation of hexagonal ZnO and flower shaped agglomeration of ZnO/CuO nano-flakes with uniform production. The strong UV emission peak observed at around 380 nm show enhanced intensity for ZnO/CuO nanocomposite. Compared to ZnO nanoparticles, ZnO/CuO composites exhibit good transparency with sharp absorbance edges. The simplicity of synthesis route coupled with better optical and PL emission properties propose the microwave synthesized ZnO/CuO nanocomposite powders a promising material for optoelectronic devices.     

ZnO@Porous Media, Their PL and Laser Effect

Optoelectronic nanocomposites are a new class of materials, which exhibit very interesting and particular properties and attract a growing attention due to their potential applications in information storage and optoelectronic devices. Zinc oxide, ZnO, is one of the most interesting binary semiconductor （3.37 eV） with very important optical properties, which can be used in the fields such as short wavelength lasers, blue light emitting diodes, UV detectors, gas sensors, etc. This paper reviews the very recent progress in the prepa- ration of silica-based ZnO nanocomposites. After an introduction reviewing the theoretical background, the article will begin with a survey of the optical properties and the quantum size effect （QSE） of ZnO/SiO2 nanocomposites prepared by the inclusion of ZnO nanoclusters inside silica mesoporous materials. The second part will focus on one of the most interesting properties of ZnO/SiO2 nanocomposites, which is the random lasing effect after one- and two-photon excitation. The final part will deal with the introduction of ZnO nanoparticles inside microporous zeolites and the observation of QSE. For comparison, the photoluminescence （PL） and QSE properties of ZnS nanoparticles occluded in mesoporous media are also described. New potential applications will be discussed since short-wavelength devices are required by industry to design, for instance, new information storage supports and biolabelling devices.     

Chiral Nanoceramics

The study of different chiral inorganic nanomaterials has been experiencing rapid growth during the past decade, with its primary focus on metals and semiconductors. Ceramic materials can substantially expand the range of mechanical, optical, chemical, electrical, magnetic, and biological properties of chiral nanostructures, further stimulating theoretical, synthetic, and applied research in this area. An ever-expanding toolbox of nanoscale engineering and self-organization provides a chirality-based methodology for engineering of hierarchically organized ceramic materials. However, fundamental discoveries and technological translations of chiral nanoceramics have received substantially smaller attention than counterparts from metals and semiconductors. Findings in this research area are scattered over a variety of sources and subfields. Here, the diversity of chemistries, geometries, and properties found in chiral ceramic nanostructures are summarized. They represent a compelling materials platform for realization of chirality transfer through multiple scales that can result in new forms of ceramic materials. Multiscale chiral geometries and the structural versatility of nanoceramics are complemented by their high chiroptical activity, enantioselectivity, catalytic activity, and biocompatibility. Future development in this field is likely to encompass chiral synthesis, biomedical applications, and optical/electronic devices. The implementation of computationally designed chiral nanoceramics for biomimetic catalysts and quantum information devices may also be expected.     

Thermoplastic polymer nanocomposites for applications in optical devices

Polymer optical fibres (POF) have superior properties compared to glass fibres like e.g. high flexural strength, uncomplicated mechanical machining and inexpensive mass production. Dispersion of nanoscaled ceramic fillers in polymers allows the modification of the refractive index depending on the ceramic used and the aspired application. Current work deals with the development of a process chain to tailor the refractive index of PMMA using a UV-curable reactive resin and ceramic nanopowders as well as with the ageing behaviour of polymer nanocomposites. Improved dispersion techniques applying high shear forces to deagglomerate the ceramic powders lead to a refractive index shift depending on the ceramic fillers maintaining a transparency of resulting polymer nanocomposites sufficient for optical applications in the visible (633 nm) and in the infrared (1550 nm) regime. Optical devices were obtained using reaction moulding of the modified polymer nanocomposites as rapid prototyping method.     

Optical Fluoride Nanoceramics

Inorganic Materials - This paper examines methods for the fabrication of optical fluoride nanoceramics and the compaction behavior of precursor powders. We discuss the basic drawbacks to the...     

Radiation methods in nanotechnology

This paper considers the state of the art in the application of radiation technology for obtaining and investigating new functional materials, devices, and systems of nanometer sizes where the key role is played by the quantum properties of the substance. This concerns in the first place the production of ion-track membranes, polymeric nanocomposites and nanogels, three-dimensional nanostructures, finely dispersed powders, semiconductor nanometric structures, carbon nanostructures, microchips of the new generation based on graphene transistors, etc.     

高强度羟基磷灰石纳米陶瓷的构建及其促成骨细胞活性研究

本研究旨在研究羟基磷灰石(HA)前驱粉体与所制备陶瓷之间的关系, 制备具有优良力学性能及成骨活性的HA纳米陶瓷。采用三种HA前驱粉体, 即40 ℃合成的HA-40粉体、以PEG为模板40 ℃合成的HA-40PEG粉体和80 ℃合成的HA-80粉体, 系统研究了前驱粉体对陶瓷性能的影响。结果显示, HA-40、HA-40PEG和HA-80粉体制备的陶瓷晶粒尺寸分别为(217.87±57.53)、(123.22±20.16)和(316.65±68.91) nm, 表明HA-40PEG有利于HA纳米陶瓷的制备。烧结得到的HA-40PEG纳米晶陶瓷表现出良好的力学性能, 与另外两种亚微米晶陶瓷(HA-40和HA-80)相比, 其抗压强度更高(~300 MPa)。细胞研究结果显示, HA-40PEG比HA-40和HA-80更能促进MC3T3-E1前成骨细胞的铺展和增殖。由此可知, 前驱粉体合成是影响HA陶瓷性能的关键因素, 纳米晶构建有利于同时提高其力学性能和生物学性能。     

Amino acid catalyzed biomimetic preparation of tin oxide-germania nanocomposites and their characterization

The efficiency of growth of nanocrystalline tin oxide-germania nanocomposites at room temperature was investigated in the presence of the amino acids arginine, histidine, and lysine under varying conditions. The preparation of tin oxide nanoparticles under similar conditions was also examined. It was observed that of the three amino acids, arginine was the most efficient and formed higher yields of the products. Calcination of the products led to crystalline materials. The growth was carried out using a biological approach under mild conditions at room temperature. The morphology and the crystallinity of the products were examined by transmission electron microscopy and atomic force microscopy. The optical properties of the nanocomposites were characterized by fluorescence, and ultraviolet-visible spectroscopy. The nitrogen adsorption studies indicate that the nanocomposites obtained were mesoporous in nature. The nanocomposites exhibited high BET surface area. Such materials could be potentially useful for the development of improved gas sensor devices and optical devices.