碳纳米管可控制备的过去、现在和未来

碳纳米管独特的几何和电子结构使其具有丰富优异的性质,因此在过去的二十余年备受研究者的关注。然而,碳纳米管结构的多样性成为其从实验室走到产业化的最大阻碍,结构决定性质,制备决定未来,完善的结构控制制备技术将成为碳纳米管基础研究和产业化应用中至关重要的一环。本文首先对碳纳米管的结构进行描述,然后综述了碳纳米管的结构可控制备方法和溶液纯化分离技术,提出未来理想的碳纳米管制备之路是将碳纳米管精细结构控制方法与宏量制备技术相结合,在降低碳纳米管生产成本的同时,提高其纯度,并建立碳纳米管产品的标准。最后,展望了碳纳米管的杀手锏级应用和该领域的机遇和挑战。     

石墨烯/碳纳米管复合材料的制备及应用进展

石墨烯和碳纳米管都是纳米尺寸的碳材料,具有极大的比表面积、良好的导电性以及优秀的机械性能等特性. 选择合适的方法制备出石墨烯/碳纳米管复合材料,它们之间可以产生一种协同效应,使其各种物理化学性能得到增强,因而这种复合材料在很多领域有着极大的应用前景. 以石墨烯/碳纳米管复合材料为综述对象,详细地介绍了它的制备、掺杂和应用等方面的进展,同时也对其发展前景进行了展望. 这种复合材料不仅被成功地应用在电容器、光电器件、储能电池、电化学传感器和其它领域,而且也会在这些领域内深化并向其它领域延伸.     

聚苯乙烯/碳纳米管复合材料研究进展

聚苯乙烯/碳纳米管复合材料是近年来开发的新型聚合物基复合材料,具有独特的一维纳米管分散微结构,往往表现出比纯聚苯乙烯更好的机械力学性能、电学性能和热性能等,在诸多领域具有广泛的应用前景.本文首先简要介绍了碳纳米管的结构特点、制备与纯化和性能,然后重点阐述了聚苯乙烯/碳纳米管复合材料的几种制备方法、结构表征以及力学、电学和热性能等方面的研究进展,并对聚苯乙烯共聚物/碳纳米管复合材料的研究现状进行介绍.     

纳米金/碳纳米管复合材料修饰电极催化鲁米诺电致发光体系的研究

制备了纳米金/多壁碳纳米管(MWNT)复合材料修饰电极,并将此电极应用于鲁米诺电化学发光体系.电化学发光实验表明,此复合材料修饰电极同时具备了纳米金和碳纳米管的催化性能.此外通过电极活性表面积测算、电化学交流阻抗实验等方法研究了纳米金和碳纳米管在此体系催化过程中的作用.纳米金/碳纳米管修饰电极具有良好的重现性,可以广泛应用于鲁米诺电化学发光测定体系.     

水热法制备氧化镉纳米线内填充碳纳米管阵列

碳纳米管及其复合材料具有独特且优异的性能,是纳米科学领域的研究热点.以往的大量研究主要关注碳纳米管外壁的修饰和复合.近年来,一些理论和实验研究显示,填充于碳纳米管纳米孔道中的物质具有很多特殊的性质与应用.然而传统的填充方法存在填充条件苛刻、填充效率低、重现性差等缺点,极大地限制了该类型复合材料的制备与应用.本文采用一种高度取向排列的碳纳米管/环氧树脂多孔复合薄膜为原料,结合水热法成功地在直径仅8 nm的碳纳米管孔道内部原位填充了长度超过100 nm的氧化镉纳米线,并通过高分辨透射电子显微镜(the high-resolution transmission electron microscopy,HRTEM)、能量弥散X-射线光谱(energy dispersive X-ray spectroscopy,EDX)等方法对实验结果进行表征.与传统填充方法相比,我们的方法具有操作简便、填充效率高等优点,未来可推广到制备其他复杂结构的碳纳米管内填充复合材料,用于新型传感器、电极材料及光学器件等.     

碳纳米管@SiO_2@Ag纳米复合材料的制备及其表面增强拉曼效应

本文以SiO2为中间层,在多壁碳纳米管(MWCNTs)表面负载Ag纳米粒子,制备出CNTs@SiO2@Ag纳米复合材料,并采用TEM、XRD、UV-Vis、XPS等对纳米复合材料的结构、形貌和成分进行了表征,同时对该纳米复合材料的表面增强拉曼散射(Surface-enhanced Raman scattering,SERS)效应进行了研究。结果显示,Ag纳米颗粒有效提高了CNTs的SERS活性,纳米复合材料的拉曼峰强度是单纯CNTs拉曼峰强的近5倍。进一步研究了吸附罗丹明6G生物染料分子的SERS光谱,结果表明R6G分子的拉曼信号的质量与强度得到显著提高。因此,所制备的CNTs@SiO2@Ag纳米复合材料有望作为SERS的活性基底,应用于生物无损检测领域。     

ZnO-CNTs纳米复合材料的制备及性能表征

以醋酸锌(Zn(CH3COO)2•2H2O)和经硝酸处理过的碳纳米管(CNTs)为原料, 一缩二乙二醇(DEG)为溶剂, 采用溶胶法制备得到ZnO-CNTs纳米复合材料, 并通过XRD、TEM、SEM、IR、PL等手段对样品进行了表征, TEM及SEM结果显示, 负载在碳纳米管上的氧化锌纳米颗粒的尺寸小于25 nm. 讨论了反应时间、反应温度等因素对产品形貌的影响, 并对复合材料的光致发光效应及其形成机理进行了初步的探讨. PL结果表明, 相对于纯ZnO, ZnO-CNTs纳米复合材料的近紫外发射峰峰位发生了明显的蓝移.     

基于纳米碳填料可拉伸导电聚合物复合材料的制备

碳系材料具有导电性强、稳定性好、价格低廉等优点,被广泛用于制备可拉伸导电复合材料,并且在可拉伸、可穿戴电子设备等领域有巨大的应用潜力,引起了研究者的密切关注。本文介绍了碳系材料的种类,主要有炭黑、碳纳米管和石墨烯等;总结了3种纳米复合材料的主要制备工艺:原位聚合法、熔融共混法和溶液混合法,并介绍了传统印刷技术和新型打印技术。分析了复合材料的导电机理,介绍了渗流阈值理论;并重点探讨了其在可拉伸传感器和可拉伸能量储存设备领域的应用。针对基于纳米碳填料制备的可拉伸导电聚合物复合材料指出目前研究的不足之处:导电填料分散性差、导电网络不稳定和无法大规模生产等,并提出了多种解决方案。对基于纳米碳填料制备的可拉伸导电聚合物复合材料在微型化、可拉伸、可穿戴电子设备领域的应用前景作出了展望。     

碳纳米管/聚苯胺复合材料的制备及应用研究进展

碳纳米管/聚苯胺复合材料因其独特的电磁学、热力学和机械性能,在很多领域具有潜在应用价值.本文作者对近年来该复合材料的制备方法、性能及应用方面的研究进展进行了综述.     

取向碳纳米管/高分子新型复合材料的制备及应用

碳纳米管/高分子复合材料已经被广泛研究, 但长期以来存在一个共同而关键的挑战, 即碳纳米管无规聚集, 结构难以调控, 性能无法满足应用需要. 本工作提出了制备取向碳纳米管/高分子复合材料的一种新方法, 获得块状、膜状、纤维状复合材料, 制备的关键步骤是通过化学气相沉积法合成可纺的高质量碳纳米管阵列. 该方法简单易行, 具有较好的普适性. 由于碳纳米管取向排列, 复合材料具有优异的物理性能, 如碳纳米管取向后复合材料的机械强度和导电率可分别提高一个和三个数量级. 在此基础上, 进一步探讨取向碳纳米管/高分子复合材料作为新型电极在有机太阳能电池中的应用.     

A Review Featuring Fabrication,Properties and Applications of Carbon Nanotubes (CNTs) Reinforced Polymer and Epoxy Nanocomposites

Carbon nanotubes (CNTs) have long been recognized as the stiffest and strongest man-made material known to date.In addition,their high electrical conductivity has roused interest in the areas of electrical appliances and communication related applications.However,due to their miniature size,the excellent properties of these nanostructures can only be exploited if they are homogeneously embedded into light-weight matrices as those offered by a whole series of engineering polymers.In order to enhance their chemical affinity to engineering polymer matrices,chemical modification of the graphitic sidewalls and tips is necessary.The mechanical and electrical properties to date of a whole range of nanocomposites of various carbon nanotube contents are also reviewed in this attempt to facilitate progress in this emerging area.Recently,carbonaceous nano-fillers such as graphene and carbon nanotubes (CNTs) play a promising role due to their better structural and functional properties and broad range of applications in every field.Since CNTs usually form stabilized bundles due to van der Waals interactions,they are extremely difficult to disperse and align in a polymer matrix.The biggest issues in the preparation of CNTs reinforced composites reside in efficient dispersion of CNTs into a polymer matrix,the assessment of the dispersion,and the alignment and control of the CNTs in the matrix.An overview of various CNT functionalization methods is given.In particular,CNT functionalization using click chemistry and the preparation of CNT composites employing hyperbranched polymers are stressed as potential techniques to achieve good CNT dispersion.In addition,discussions on mechanical,thermal,electrical,electrochemical and applications ofpolymer/CNT composites are also included.     

Detection of Trace Zinc by an Electrochemical Microsensor based on Carbon Nanotube Threads

Carbon nanotubes (CNTs) have attracted intense interest due to their excellent properties, such as increased electrode surface area, fast electron transfer rate, significant mechanical strength and good chemical stability. CNT threads, spun from shorter CNTs, inherit the advantages of CNTs, while avoiding the potential toxicity caused by individual CNTs. In this work, microelectrodes based on CNT threads were used to detect trace zinc by anodic stripping voltammetry with an estimated detection limit of 1.4 nM without mercury or bismuth films. CNT threads showed promise for measuring trace metals in small sample volumes without stirring such as encountered in some in vivo and in vitro applications.     

Application of carbon nanotubes in extraction and chromatographic analysis: A review

Carbon nanotube (CNT), a well-known carbon-based nanomaterial has drawn much attention in many application fields including chemistry in the last few decades. Many researchers and scientists have shown huge interest to improve the extraction methodologies and adopt their applications in combination with chromatography technique. With respect to this, the exceptional applications of CNTs have been introduced as extraction sorbent due to their excellent inborn physical and chemical properties. In particular, CNTs have consistently been used as adsorbents in various techniques including solid-phase micro-extraction, solid-phase extraction, micro dispersive slid phase extraction, magnetic dispersive solid phase extraction, analytes enrichment, sample fractionation and clean-up as well as support for many derivatization reactions. Many research papers have discussed the successful use of CNTs to overcome the limitations of the extraction techniques due to their excellent sorbent capacity. In addition, considering the clear need to make chromatographic technique more successful, the applications of CNTs have been reported in the literatures in details as stationary and pseudo-stationary phases for the separation and extraction of challenging compounds. Because of the higher thermal and chemical stability, CNTs have been anticipated as stationary phase modifier for chromatographic applications to avoid bleeding of the columns and enable the analysis even at very high temperature (1200 °C). In liquid chromatography CNTs have primarily been used in combination with other packing materials (silica) and sometimes incorporated in a porous polymeric monolith. Therefore, the recent utilizations of CNTs as extraction materials and stationary phases have been illustrated in the current review and a table listing the details applications of CNTs in aforementioned field is provided as well. We believe that the review will help researcher to gain vast knowledge about application of carbon nanotubes in the field of separation chemistry.     

Electrochemistry and electroanalytical applications of carbon nanotubes: a review.

This review addresses recent developments in electrochemistry and electroanalytical chemistry of carbon nanotubes (CNTs). CNTs have been proved to possess unique electronic, chemical and structural features that make them very attractive for electrochemical studies and electrochemical applications. For example, the structural and electronic properties of the CNTs endow them with distinct electrocatalytic activities and capabilities for facilitating direct electrochemistry of proteins and enzymes from other kinds of carbon materials. These striking electrochemical properties of the CNTs pave the way to CNT-based bioelectrochemistry and to bioelectronic nanodevices, such as electrochemical sensors and biosensors. The electrochemistry and bioelectrochemistry of the CNTs are summarized and discussed, along with some common methods for CNT electrode preparation and some recent advances in the rational functionalization of the CNTs for electroanalytical applications.     

A short, rigid, structurally pure carbon nanotube by stepwise chemical synthesis

The inaccessibility of uniform-diameter, single-chirality carbon nanotubes (CNTs) in pure form continues to thwart efforts by scientists to use these ultrathin materials in innovative applications that could revolutionize nanoscale electronics. Stimulated by the challenge to address this long-standing problem, we and other organic chemists have envisioned a new production strategy involving the controlled elongation of small hydrocarbon templates, such as hemispherical nanotube end-caps, prepared by bottom-up chemical synthesis; the diameter and rim structure encoded in the template would dictate the diameter and chirality of the resulting CNT. Toward that objective, a short [5,5] CNT has now been synthesized by stepwise chemical methods. This C(50)H(10) geodesic polyarene has been isolated, purified, crystallized, and fully characterized by NMR spectroscopy, UV-vis absorption spectroscopy, high resolution mass spectrometry, and X-ray crystallography.     

Carbon nanotubes as nanocarriers in medicine

Carbon nanotubes (CNTs) possess outstanding properties and a unique physicochemical architecture, which may serve as an alternative platform for the delivery of various therapeutic molecules. This review focuses on recent progress in the field of CNTs for biomedical applications. After a short, general physico-chemical introduction to CNTs, we introduce different methods for CNT surface modification, facilitating their dispersions in physiological solutions, on the one hand, and binding a wide range of molecules or drug-loaded liposomes, on the other. We summarize imaging evidences on the structure of CNT-drug conjugates and their relevant uptake mechanisms by the cell. Lastly, we review current repots on CNT toxicity and new developments in CNT-based medical applications: photo-thermal therapy, drug delivery and gene therapy.     

Chemical and structural characterization of carbon nanotube surfaces

To utilize carbon nanotubes (CNTs) in various commercial and scientific applications, the graphene sheets that comprise CNT surfaces are often modified to tailor properties, such as dispersion. In this article, we provide a critical review of the techniques used to explore the chemical and structural characteristics of CNTs modified by covalent surface modification strategies that involve the direct incorporation of specific elements and inorganic or organic functional groups into the graphene sidewalls. Using examples from the literature, we discuss not only the popular techniques such as TEM, XPS, IR, and Raman spectroscopy but also more specialized techniques such as chemical derivatization, Boehm titrations, EELS, NEXAFS, TPD, and TGA. The chemical or structural information provided by each technique discussed, as well as their strengths and limitations. Particular emphasis is placed on XPS and the application of chemical derivatization in conjunction with XPS to quantify functional groups on CNT surfaces in situations where spectral deconvolution of XPS lineshapes is ambiguous.      

Effect of elongational flow on morphology and properties of polymer/CNTs nanocomposite fibers

Carbon nanotubes (CNTs) have been attracting increasing interest for the fabrication of polymer‐based nanocomposites because of their excellent properties. Traditional methods for the preparation of polymer/CNTs nanocomposites are in situ polymerization, solution blending, and melt mixing. The achievement of a good CNT dispersion and a percolation network is important in order to obtain better mechanical and electrical properties. However, the rheological behavior of polymer/CNTs systems, in particular regarding the extensional flow, has not been much investigated so far. In this work we present, for the first time, rheological data in non‐isothermal extensional flow and an investigation on the effect of the extensional flow upon the final properties of several polymer/CNTs systems was carried out as well. Extensional flow led to higher mechanical properties and higher melt strength, but only a slightly reduced breaking stretching ratio. This result could be particularly interesting in the view of potential industrial applications such as film blowing and spinning. Morphological analyses also showed higher degrees of dispersion and variation in the CNTs final dimensions. Copyright © 2010 John Wiley & Sons, Ltd.     

Carbon nanotube--conducting-polymer composite nanowires

Polypyrrole/carbon nanotube (PPy/CNT) composite nanowires were prepared by a template-directed electrochemical synthetic route, involving plating of PPy into the pores of a host membrane in the presence of shortened and carboxylated CNT dopants (without added electrolyte). Cyclic voltammetric growth profiles indicate that the CNT is incorporated within the growing nanowire and serves as the sole charge-balancing "counterion". Transmission electron microscopy images indicate high-quality straight PPy/CNT nanowires with a smooth and featureless surface and a uniform diameter. The presence of the CNT dopant imparts high conductivity (Ohmic I-V behavior) onto these PPy/CNT nanowires. By combining the attractive properties of CNTs, conducting polymers, and nanowires, the new nanocomposite opens up new opportunities, ranging from chemical sensors to molecular electronic devices.