共查询到19条相似文献,搜索用时 125 毫秒
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多壁碳纳米管/环氧有机硅树脂吸波涂层的介电和吸波性能研究 总被引:2,自引:0,他引:2
研究了不同直径和含量多壁碳纳米管填充环氧有机硅树脂吸波涂层在2~18GHz频率范围内的介电和吸波性能.可以得到吸波涂层的介电常数随着碳纳米管含量的增加而增大.当碳纳米管含量相同时,吸波涂层介电常数随着碳纳米管直径的增加而增大.当碳纳米管含量大于5wt%时,吸波涂层的介电常数在低频急剧增加,且随频率增大而减少,出现频散效应.反射率测试结果表明:当涂层中多壁碳纳米管含量为10wt%、厚度为2mm时,吸波涂层的最大吸收峰随碳纳米管直径的增大向低频移动.多壁碳纳米管填充环氧有机硅树脂吸波涂层的吸波性能在7~14GHz范围内可达到-10dB,具有较好的吸波效果. 相似文献
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描述了一种把阵列式排列的碳纳米管膜完整地从沉积基底上逐层分离组装到软的新基底上的技术。用扫描电镜研究了被分离的碳纳米管膜的形貌、粘结层的特点,对被分离的膜的表面导电性能,膜与新基底体系的体积导电性能分别做了测试。电镜形貌分析表明构成碳纳米管膜的碳纳米管在被分离后可以保持原来的形貌,也可以呈弯曲状,这取决于作用在碳纳米管膜上的压力。电阻测试表明膜的表面电忸为10欧姆,而膜与基底体系的体积电阻在有粘结层条件下小于0.1欧姆。 相似文献
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碳纳米管是近年来国内外广泛关注的一类纳米材料,具有一维特征孔道结构,能够有效促进液体分子的传输速率,是理想的海水淡化膜分离材料。通过将其引入到常用的海水淡化膜基质中,借以提高膜的分离性能,逐渐成为膜分离领域的一个研究热点。综述了碳纳米管在海水淡化膜分离材料中的应用与研究进展,介绍了碳纳米管的结构并阐述了其应用于海水淡化膜分离的优异性能,总结了碳纳米管在反渗透、正渗透、膜蒸馏中的应用研究现状并分析了碳纳米管在反渗透、正渗透、膜蒸馏应用中的挑战,探讨了碳纳米管在海水淡化膜分离材料中的应用潜力。 相似文献
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DNA-assisted dispersion and separation of carbon nanotubes 总被引:2,自引:0,他引:2
Zheng M Jagota A Semke ED Diner BA McLean RS Lustig SR Richardson RE Tassi NG 《Nature materials》2003,2(5):338-342
Carbon nanotubes are man-made one-dimensional carbon crystals with different diameters and chiralities. Owing to their superb mechanical and electrical properties, many potential applications have been proposed for them. However, polydispersity and poor solubility in both aqueous and non-aqueous solution impose a considerable challenge for their separation and assembly, which is required for many applications. Here we report our finding of DNA-assisted dispersion and separation of carbon nanotubes. Bundled single-walled carbon nanotubes are effectively dispersed in water by their sonication in the presence of single-stranded DNA (ssDNA). Optical absorption and fluorescence spectroscopy and atomic force microscopy measurements provide evidence for individually dispersed carbon nanotubes. Molecular modelling suggests that ssDNA can bind to carbon nanotubes through pi-stacking, resulting in helical wrapping to the surface. The binding free energy of ssDNA to carbon nanotubes rivals that of two nanotubes for each other. We also demonstrate that DNA-coated carbon nanotubes can be separated into fractions with different electronic structures by ion-exchange chromatography. This finding links one of the central molecules in biology to a technologically very important nanomaterial, and opens the door to carbon-nanotube-based applications in biotechnology. 相似文献
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碳纳米管表面活性化及其在生物医药中的应用 总被引:1,自引:0,他引:1
综合了国内外文献资料,介绍了碳纳米管的表面处理的方法,对不同处理方法对碳纳米管带来的物理化学变化进行了综述;重点介绍了处理后的碳纳米管在生物医药领域的应用;最后对碳纳米管表面活化方法选择进行了总结. 相似文献
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作为重要的纳米功能纤维,碳纳米管有着令人振奋的广阔的应用前景,引起了世界范围内研究人员的广泛关注.综述了国内外碳纳米管技术的最新研究进展,比较了电弧放电、激光烧蚀以及化学气相沉积等3种主要的碳纳米管合成技术,并着重讨论了当前流行的化学气相沉积法,探讨了拉曼散射、激光诱导荧光、瑞利散射等分子光谱技术在碳纳米管表征中的应用,介绍了碳纳米管出色的力学、机电、场发射、电化学等特性以及基于碳纳米管的电子器件如场效应管、单电子管等. 相似文献
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聚合物/碳纳米管复合材料研究进展 总被引:10,自引:0,他引:10
聚合物/碳纳米管复合材料近年来引起人们广泛的关注。本文综述了聚合物/碳纳米管复合材料的研究进展,重点介绍了聚合物/碳纳米管复合材料的类型、制备方法及力学、电学和光学性能等。 相似文献
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Separation of single-walled carbon nanotubes (SWNTs), according to their electronic characteristics, is essential to the development of molecular electronics, including field-effect transistors. Recent efforts by many groups have used non-covalent and covalent sidewall chemistry to probe differential reactivity in metallic and semiconducting nanotubes. These chemically based methods may more easily effect the bulk separation of tubes, as compared with physical techniques associated with (i) alternating current dielectrophoresis as well as (ii) the current-induced oxidation of metallic nanotubes, that have recently been reported as alternative methods of achieving chiral separations of nanotubes. Exploration of these types of reactions is critical for the development of interesting chemical and physical properties at the interface between molecules and materials as well as for establishing protocols for the selective functionalization of nanotubes. 相似文献
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A comprehensive understanding of the design, synthesis, characterization, and properties of boron carbonitride nanotubes (BCN) is presented in this review. Distinctive structural and electronic properties are revealed in theoretical studies of the BCN nanotubes and compared with the properties of carbon nanotubes. In the experimental studies, BCN nanotubes have been synthesized by various techniques. For different purposes, controllable growth processes have been used to fabricate BCN nanotubes with novel structures, such as nanojunctions and filled nanotubes. Some interesting phenomena originating from the substitution of B and N atoms, such as the phase segregation, are considered theoretically and experimentally. Mainly the physical properties--field electron emission and photoluminescence--are discussed, which turn out to have potential applications in the industry. 相似文献
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Purification or separation of single-walled carbon nanotubes (SWCNTs) is one of the most fundamental steps before they are used for research and technological applications. Based on the difference of their physical and chemical properties, separation of carbon nanotubes (CNTs) can be categorized into three groups: length separation, metallic and semiconducting tubes separation and chirality separation. In this review, we first briefly review the purification of CNTs and then focus on the different methods for the separation of CNTs. 相似文献