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单壁纳米碳管的研究进展 总被引:3,自引:0,他引:3
综述了当前单壁纳米碳管的研制状况,对单纳米碳管的制备方法,结构特征,性能和应用前景进行了讨论,并且对单壁纳米碳管的新制备方法-本研究组独创的有机物气相催化热解法进行论述。 相似文献
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硫促进剂对单壁纳米碳管生成的影响 总被引:9,自引:0,他引:9
研究了有机物催化热解法中硫生长促进剂对单壁纳米碳管生成的影响,结果表明,含硫生长促进剂能促进单壁纳米碳管的生成,提高产率,并改变其直径数值的分布;促进剂的添加量大,纳米碳管的直径也大。 相似文献
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纳米碳管以其独特的结构、优异的物理化学性质以及超高的力学性能而具有巨大的应用前景.单壁纳米碳管作为纳米碳管结构的基础,在纳米电子器件、单电子器件、储能材料等方面表现出了良好的性能.基于对单壁纳米碳管的研究,综述了近年来在单壁纳米碳管制备技术方面取得的最新进展,其中包括电弧放电法、化学气相沉积法以及激光蒸发法等方法,并讨论了在不同方法中影响单壁纳米碳管生长的几个关键因素. 相似文献
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以单壁纳米碳管为代表材料,对利用纳米碳管制备葡萄糖生物传感器中纳米碳管的作用和纳米碳管修饰电极的方法、酶的固定化方法及电极种类等因素对传感器性能的影响进行了研究.研究结果表明,纳米碳管的加入能有效地改善传感器的电化学性能,利用二茂铁和单壁纳米碳管共同修饰电极所制得的传感器的性能要好于仅用单壁纳米碳管修饰电极制得的传感器.在酶的固定化方法中,戊二醛交联法要略好于明胶包埋法;而利用铂电极制备出的生物传感器对葡萄糖的响应电流要明显高于利用金电极和玻碳电极制备出的生物传感器.这些结论对于开发纳米碳管在生物传感领域及生命科学相关领域的应用有参考价值. 相似文献
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采用聚乙烯醇(PVA)树脂炭化的方法,制备了PVA树脂炭包覆硅/不同纳米碳管复合材料,通过X-射线、高分辩电镜观察和电化学性能测试等手段比较研究了单壁、双壁和多壁纳米碳管作为弹性导电网络缓解硅在充放电过程中体积变化方面的效果。结果表明,单壁纳米碳管和双壁纳米碳管比多壁纳米碳管能够更好地缓解硅在循环过程中产生的结构和体积变化,这主要是因为其长径比大,缠裹效果更好。单壁纳米碳管和双壁纳米碳管具有相近的直径、长径比及宏观分布形式,但在循环过程中,双壁纳米碳管的结构稳定性好于单壁纳米碳管,进而其缓解硅结构变化的效果更好。 相似文献
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Yue B Wang Y Huang CY Pfeffer R Iqbal Z 《Journal of nanoscience and nanotechnology》2007,7(3):994-1000
A novel method to synthesize single-wall carbon nanotube (SWNT)/poly(methyl methacrylate) (PMMA) nanocomposite by in-situ polymerization in supercritical CO2 is presented. The surfaces of the SWNT bundles were first functionalized with amino ethyl methacrylate (AEMA) followed by co-polymerization with methyl methacrylate. Supercritical fluid enhanced the diffusivity of monomer and facilitated the growth of tethered PMMA chains near the entanglement area and the interstitial space of the SWNT bundles. Partial debundling and disentanglement of the SWNT bundles and an enhanced dispersion in the polymer matrix were observed under SEM and TEM. After the removal of the polymer matrix physically attached to the nanotubes, it is found that the nanotubes were covered by tethered PMMA chains, which were a few nanometers in thickness. This work creates a route for improving impregnation and dispersion in SWNT composites; the same process can be extended to other vinyl polymers. 相似文献
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Gadagkar V Saha S Muthu DV Maiti PK Lansac Y Jagota A Moravsky A Loutfy RO Sood AK 《Journal of nanoscience and nanotechnology》2007,7(6):1753-1759
We have used Raman spectroscopy to study the behavior of double-walled carbon nanotubes (DWNT) under hydrostatic pressure. We find that the rate of change of the tangential mode frequency with pressure is higher for the sample with traces of polymer compared to the pristine sample. We have performed classical molecular dynamics simulations to study the collapse of single (SWNT) and double-walled carbon nanotube bundles under hydrostatic pressure. The collapse pressure (pc) was found to vary as 1/R3, where R is the SWNT radius or the DWNT effective radius. The bundles showed approximately 30% hysteresis and the hexagonally close packed lattice was completely restored on decompression. The pc of a DWNT bundle was found to be close to the sum of its values for the inner and the outer tubes considered separately as SWNT bundles, demonstrating that the inner tube supports the outer tube and that the effective bending stiffness of DWNT, D(DWNT) - 2D(SWNT). 相似文献
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Fadel TR Steenblock ER Stern E Li N Wang X Haller GL Pfefferle LD Fahmy TM 《Nano letters》2008,8(7):2070-2076
Efficient immunotherapy can be accomplished by expanding T cells outside the body using single walled carbon nanotube (SWNT) bundles presenting antibody stimuli. Owing to the large surface area of these bundles, which can reach 1560 m (2)/g, T cell stimulating antibodies such as anti-CD3, can be presented at high local concentrations inducing potent activation of T cells. We show that anti-CD3 adsorbed onto SWNT bundles stimulate cells more effectively than equivalent concentrations of soluble anti-CD3. Stimulation by antibody adsorbed onto SWNT is significantly higher than other high surface area materials (activated carbon, polystyrene, and C60 nanoparticles), suggesting unique properties of SWNT bundles for stimuli presentation. We demonstrate the surface area tunability of these bundles by chemical treatment and its effect on antibody adsorption and subsequent T cell activation. In addition, the T cell response varied with the concentration of SWNT in a concentration dependent manner. Antibody stimuli adsorbed onto SWNT bundles represent a novel paradigm for efficient activation of lymphocytes, useful for basic science applications and clinical immunotherapy. 相似文献
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Maoshuai He Shuchen Zhang Qianru Wu Han Xue Benwu Xin Dan Wang Jin Zhang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(9)
A major obstacle for the applications of single‐walled carbon nanotubes (SWNTs) in electronic devices is their structural diversity, ending in SWNTs with diverse electrical properties. Catalytic chemical vapor deposition has shown great promise in directly synthesizing high‐quality SWNTs with a high selectivity to specific chirality (n, m). During the growth process, the tube–catalyst interface plays crucial roles in regulating the SWNT nucleation thermodynamics and growth kinetics, ultimately governing the SWNT chirality distribution. Starting with the introduction of SWNT growth modes, this review seeks to extend the knowledge about chirality‐selective synthesis by clarifying the energetically favored SWNT cap nucleation and the threshold step for SWNT growth, which describes how the tube–catalyst interface affects both the nucleus energy and the new carbon atom incorporation. Such understandings are subsequently applied to interpret the (n, m) specific growth achieved on a variety of templates, such as SWNT segments or predefined molecular seeds, transition metal (Fe, Co and Ni)‐containing catalysts at low reaction temperatures, W‐based alloy catalysts, and metal carbides at relatively high reaction temperatures. The up to date achievements on chirality‐controlled synthesis of SWNTs is summarized and the remaining major challenges existing in the SWNT synthesis field are discussed. 相似文献
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Mallick G Griep M Lastella S Sahoo S Hirsch S Ajayan PM Karna SP 《Journal of nanoscience and nanotechnology》2010,10(9):6062-6066
Current rectification property of as-grown single-walled carbon nanotubes (SWNTs) is investigated. The SWNTs are grown by chemical vapor deposition (CVD) process. The process allowed to grow long strands of SWNT bundles, which are then used to fabricate multiple arrays of switching devices with the channel length of 3, 5, 7 and 10 microm on a 15 mm x 15 mm SiO2 on Si substrate. Regardless of the channel length, a majority of the fabricated devices show current rectification characteristics, with high throughput of current (I) in the forward bias (V) giving the forward and reverse current ratio (Ifor/Irev) of approximately 10(6). Atomic force microscopic (AFM) analysis of the device structure and surface topology of SWNT suggest the observed rectification of current to possibly result from (a) cross-tube junctions, (b) a mixture of metallic and semiconducting tubes in the SWNT bundles, and/or (c) chirality change along a single tube. The exact mechanism underlying the observed rectification could not be conclusively established. However, the analyses of the experimental results strongly suggest the observed rectification to result from Schottky-type diode properties of SWNTs with mixed chirality along the tube. 相似文献
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《Journal of Experimental Nanoscience》2013,8(1):66-76
Quantification using scanning electron microscopy (SEM) of single walled carbon nanotubes (SWNTs) grown per unit area using a Co-Fe (50:50) catalyst system, prepared by the incorporation of the appropriate metal salts into a Spin-On Glass substrate, at 900°C. The effects of substrate, as well as catalyst precursor concentration, were investigated. SWNT growth density is maximised with a catalyst precursor concentration of ≥2.5 mM, associated with the formation of catalyst nanoparticles of a critical size for SWNT nucleation. Samples were subjected to secondary growth, using a range of H2:CH4 ratios to determine the optimum precursor composition. It was found that nucleation and growth stages are optimal under different conditions. Optimum conditions for nucleation resulted in >10× increase in SWNT density. Optimisation is dependent on temperature and the partial pressure of reagent gas species. 相似文献
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Endo M Hayashi T Kim YA Muramatu H Ezaka M Watts PC Nishimura K Tsukada T 《Journal of nanoscience and nanotechnology》2004,4(1-2):132-135
We describe a possible route for large-scale synthesis of single wall carbon nanotubes (SWNTs) by a combination of the substrate and floating methods. The template prohibits metal particle aggregation, resulting in high-purity SWNT growth, and the three-dimensional floating seeded state of the template induces improved yields of SWNTs in a semi-continuous system. The SWNTs obtained by this method exhibit large variations of texture (isolated tubes and bundles) and a wide range of diameters (0.4-4 nm). 相似文献
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Changhong Ke Meng Zheng Guangwen Zhou Weili Cui Nicola Pugno Ronald N. Miles 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(3):438-445
An in situ electron microscopy study is presented of adhesion interactions between single‐walled carbon nanotubes (SWNTs) by mechanically peeling thin free‐standing SWNT bundles using in situ nanomanipulation techniques inside a high‐resolution scanning electron microscope. The in situ measurements clearly reveal the process of delaminating one SWNT bundle from its originally bound SWNT bundle in a controlled‐displacement manner and capture the deformation curvature of the delaminated SWNT bundle during the peeling process. A theoretical model based on nonlinear elastica theory is employed to interpret the measured deformation curvatures of the SWNTs and to quantitatively evaluate the peeling force and the adhesion strength between bundled SWNTs. The estimated adhesion energy per unit length for each pair of neighboring tubes in the peeling interface based on our peeling experiments agrees reasonably well with the theoretical value. This in situ peeling technique provides a potential new method for separating bundled SWNTs without compromising their material properties. The combined peeling experiments and modeling presented in this paper will be very useful to the study of the adhesion interactions between SWNTs and their nonlinear mechanical behaviors in the large‐displacement regime. 相似文献
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López-Pastor M Domínguez-Vidal A Ayora-Cañada MJ Simonet BM Lendl B Valcarcel M 《Analytical chemistry》2008,80(8):2672-2679
This paper presents a simple, highly efficient method for analyzing single-walled carbon nanotube (SWNT) bundles based on (1) ultrasound-assisted solubilization/dispersion of SWNTs in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, (2) encapsulation of the nanotubes in sodium dodecyl sulfate micelles, and (3) analysis by capillary electrophoresis. The process by which SWNTs disperse in the ionic liquid was studied by Raman spectroscopy. No degradation of SWNTs was observed under mild sonication conditions. The shape and position changes observed in the Raman spectral bands for the nanotubes are ascribed to debundling and interaction with the ionic liquid. Separation of solubilized SWNTs was accomplished by using a 50 mM formic acid solution at pH 2.0 as background electrolyte and a potential of -10 kV. Under these conditions, separation was completed within only 4 min. Eighteen peaks for SWNTs were identified in the analysis of commercial SWNT bundles. The two types of bundles studied exhibited distinct, highly characteristic electrophoretic profiles which could be used to control SWNTs purity. 相似文献
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Eui Yun Jang Tae June Kang Hyeoung Wook Im Dae Weon Kim Yong Hyup Kim 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(12):2255-2261
Highly uniform and large‐area single‐walled carbon‐nanotube (SWNT) networks are realized by the dip‐coating method, which is based on fundamental fluid‐dynamic phenomena such as capillary condensation and surface tension. The changes in the polarity and hydration properties of the substrate affect the morphology of the SWNT networks and result in nonlinear growth of the networks in the repetitive dip‐coating process. The density and the thickness of the SWNT networks are controlled by processing variables including number of dip coatings, concentration of SWNT colloidal solution, and withdrawal velocity. The networks have uniform sheet resistances and high optical transmittance in the visible wavelength range. 相似文献