碳纳米管的特性及应用

介绍了巴基球及碳纳米管的发现和历史 ,重点介绍了碳纳米管的基本性能和晶体结构 ,描述了碳纳米管电传导和热传导的机理。文中还介绍了碳纳米管的主要生产方法和各自的优点。根据全球碳纳米管应用研究的方向 ,对碳纳米管的应用领域进行了探讨 ,展望了碳纳米管的应用前景及商业开发价值     

碳纳米管及碳纳米管纤维的性能与应用

碳纳米管是由单层或多层石墨片卷曲而成的无缝纳米级管状壳层结构。扼要介绍了碳纳米管、碳纳米管纤维的合成方法及近几年来国内外制备的各种碳纳米管产品。碳纳米管、碳纳米管纤维由于其优良的力学、电学特性可以制成气体吸附体、生物模板、传动装置、增强复合体、催化剂载体、探测器、传感器、纳米反应器等产品，在航空、能源、医药、化学等技术领域广泛应用。     

碳纳米管及碳纳米管纤维的性能与应用

碳纳米管是由单层或多层石墨片卷曲而成的无缝纳米级管状壳层结构.扼要介绍了碳纳米管、碳纳米管纤维的合成方法及近几年来国内外制备的各种碳纳米管产品.碳纳米管、碳纳米管纤维由于其优良的力学、电学特性可以制成气体吸附体、生物模板、传动装置、增强复合体、催化剂载体、探测器、传感器、纳米反应器等产品,在航空、能源、医药、化学等技术领域广泛应用.     

碳纳米管的应用

碳纳米管具有独特的结构,优异的性能,和广泛的应心前景。本文分别从碳纳米管的力学性能、电磁性能、场致发射性能、电化学性能等方面阐述了其在相关方面的应用。     

聚苯胺原位包覆碳纳米管材料的制备及性能

在苯胺的盐酸溶液中，用过硫酸胺((NH4)2S2O8)作氧化剂，在碳纳米管上原位生成并包覆了聚苯胺，用SEM及TEM观察了包覆前后碳纳米管的结构形态，并对这种材料表面性质及微波电磁参数进行了研究。结果表明：碳纳米管／苯胺重量比为4：1时，生成的聚苯胺可完全包覆在碳纳米管上，包覆层厚度为10nm-20nm；碳纳米管经聚苯胺包覆后表面能增大，包覆后的碳纳米管在水中及固体状态时分散性明显得到改善，微波电磁吸收系数的实部(ε’，μ’)、虚部(ε”，μ”)及电磁损耗因子(tgδe=ε”/ε’，tgδm=μ”/μ’)均得到了提高，表明聚苯胺包覆后碳纳米管有望成为一种电磁波屏蔽材料。     

碳纳米管及其研究进展

本文综述了碳纳米管的发展背景、制备方法、形成机理、性能和应用 ,并对今后碳纳米管研究存在的问题作了扼要的论述     

碳纳米管及其研究进展

综述了碳纳米管的发展背景、制备及纯化方法、性能和应用 ,并对今后碳纳米管研究存在的问题作了分析和扼要的论述     

碳纳米管的电学特性及应用

碳纳米管独特而优异的电学性能,显示了它在电子学领域广阔的应用前景.在讨论碳纳米管结构及电学性质的基础上,主要介绍了碳纳米管在微电子元件、超级电容器、平面显示器和锂离子电池等方面的研究进展及应用前景.     

碳纳米管/高分子复合材料的制备及应用研究进展

将碳纳米管掺杂到聚合物母体中形成的碳纳米管/高分子复合材料具有良好的力学、导电和非线性光学性质。在聚合物中添加少量碳纳米管可以明显改变聚合物的结晶和形貌。大量研究表明,这些复合材料在诸如太阳能电池、有机发光器件、光限幅、光学开关、防护涂料以及人造肌肉等方面具有潜在的实际应用价值。文中介绍了碳纳米管/高分子复合材料的制备方法及其在高科技领域中的应用潜能。     

碳纳米管的开发现状

碳纳米管以其特殊的性能广泛应用于诸多领域,本文介绍了碳纳米管的制备方法及应用现状。     

碳纳米管的制备和吸附特性研究

采用CVD法制备了碳纳米管,并用TEM、BET吸附和~(129)Xe NMR对碳纳米管的表面和内部结构进行了表征.通过BET吸附和~(129)Xe NMR的结果对比分析,可以推断碳纳米管并非全部是中空的,而是被许多隔膜分隔成多个锥帽形空腔,这些隔膜一般为无定形碳,五元环或七元环.经过纯化后的碳纳米管具有优异的吸附性能,有望作为新一代的储氢材料.     

Electrochemical characterization of electrodeposited carbon nanotubes

Carbon nanotubes were electrodeposited in acetonitrile solution at room temperature using Cu, and Fe-Ni nanoparticles as nucleation sites on HF-etched Si(100) wafer substrate. The electrochemical behavior of the deposition was investigated by voltammetry and chronoamperometry techniques. In order to obtain the optimum growth condition, the deposition critical parameters including current density range, potential and time were studied and calculated. Carbon nanotubes with approximate external diameter of 40-100 nm were fabricated under potentiostatic condition and diffusion control at − 20 V in 4-6 h. The film crystallinity was investigated by means of X-ray diffraction and the tubes structure was revealed using scanning electron microscope and transmission electron microscope images. Raman spectroscopy was also employed to characterize the nanostructural features and single wall carbon nanotubes were detected.     

碳纳米管溶解性及其化学修饰

详细评述了增加碳纳米管在水和有机溶剂中溶解性的途径，包括单一溶剂直接分散、电子供一受体电荷转移、可溶性聚合物或表面活性剂筒状胶束包裹等非共价键相互作用和顶端开口、化学衍生以及侧壁化学修饰等共价化学修饰。指出今后一段时期碳纳米管化学的主要任务为通过非共价的或共价的化学修饰，改善碳纳米管本身的性能和用途，并耦合其他如化学的、生物的或物理的功能扩展其应用范围。进一步深入理解碳纳米管化学(尤其是其溶液化学)反应理论。     

First-principles study of electronic structure of deformed carbon nanotubes

On the basis of density functional theory, we study the electronic structures of five types of carbon nanotubes: the non-deformed (6,6) tube, the uniformly stretched tube along the tube axis, the uniformly compressed tube, the partially stretched tube and the partially compressed tube. The electron charge density increases at the compressed C-C bond of the partially stretched tube, while the density decreases at the stretched C-C bond of the partially stretched tube. In addition, the a₁ and e₁ states of the (6,6) tube contribute to the bonding along the tube axis and the a₂ and e₂ states are the bonds connecting the atoms in the same layers. Thus, the energy bands of the a₁ and e₁ states are sensitively affected by the deformation of the tubes along the tube axis.     

TiO2纳米管研究及应用进展

对TiO2纳米管的制备方法、形貌特征、晶体结构、形成机理方面作了综合评述,概述了其研究现状及最新应用进展,简述了其在各个领域的潜在应用价值.     

自组装和分散可逆的碳纳米管圆片

通过加热碳纳米管和强酸的混合物,使碳纳米管的憎水表面发生氧化.加热含经处理的碳纳米管的悬浮液,使之脱水,得到自组装的碳纳米管圆片,该圆片可直接分散.扫描电镜图显示该圆片由局部规则排列的碳纳米管构成;红外光谱和光电子谱分析表明在化学处理过程中,碳纳米管的表面产生了含氧官能团;虽然拉曼谱测出处理过程增加了缺陷,但是X射线衍射结果表明碳纳米管类似石墨的层状结构得到保留;同时研究了经处理的碳纳米管的热稳定性.这种自组装且可分散的碳纳米管圆片为研究碳纳米管结构材料和碳纳米管复合材料提供了有效途径.     

Mechanical characterization of epoxy composite with multiscale reinforcements: Carbon nanotubes and short carbon fibers

Carbon nanotubes (CNT) and short carbon fibers were incorporated into an epoxy matrix to fabricate a high performance multiscale composite. To improve the stress transfer between epoxy and carbon fibers, CNT were also grown on fibers through chemical vapor deposition (CVD) method to produce CNT grown short carbon fibers (CSCF). Mechanical characterization of composites was performed to investigate the synergy effects of CNT and CSCF in the epoxy matrix. The multiscale composites revealed significant improvement in elastic and storage modulus, strength as well as impact resistance in comparison to CNT–epoxy or CSCF–epoxy composites. An optimum content of CNT was found which provided the maximum stiffness and strength. The synergic reinforcing effects of combined fillers were analyzed on the fracture surface of composites through optical and scanning electron microscopy (SEM).     

Room temperature sensor based on carbon nanotubes and nanofibres for methane detection

Carbon nanotubes and nanofibres deposited by an electrodeposition technique were utilized to fabricate sensor material for the detection of methane. Carbon nanotubes (CNT) and nanofibres were grown on Si(0 0 1) substrate using acetonitrile (1% v/v) and water as electrolyte at an applied d.c. potential ∼20 V. Sensing properties were studied with as-deposited CNT films. It was found that the films showed good sensing properties at room temperature.     

Multi-barrier layer-mediated growth of carbon nanotubes

Variation in the height of carbon nanotubes (CNTs) grown has been co-related to the type of multi-barrier-layer used. Initially, various types of barrier-layers such as Al, Al₂O₃, Al/SiO₂, Al₂O₃/SiO₂ were prepared onto a n-type Si (100) substrate. The thickness of SiO₂ was ∼ 550 nm, where as, Al₂O₃ and Al were ∼ 15 nm thick. These samples were covered with ∼ 1 nm thick Fe catalyst layer. The coated samples were subjected to the thermal chemical vapor deposition (T-CVD) process. SEM analysis showed that, for Al₂O₃/SiO₂ barrier layers, the average height of the CNTs was ∼ 10 μm, where as, for other types of samples it was less than ∼ 1 μm. To investigate this, multi-barrier layers were characterized by dynamic secondary ion mass spectrometry (D-SIMS). The observed variation in height of CNTs is attributed to the variation in diffusivity of Fe atoms into multi-barriers-layers. The results showed that, diffusion of Fe catalyst atoms could severally affect height of CNTs.     

Synthesis of multiwalled carbon nanotubes by high-temperature vacuum annealing of amorphous carbon

Vacuum annealing of a mixture of amorphous carbon and cobalt nanoparticles supported on microporous zeolite at high-temperature results in the formation of multiwalled carbon nanotubes which are essentially filled with metal nanoparticles or nanowires as observed by transmission electron microscopy. The electronic properties of nanotubes by variable temperature ESR techniques shows that g values show little change with temperature from 77 to 327 K but the line width (ΔH_pp) of the ESR signal for nanotubes synthesized from amorphous carbon increases from 7.9 G at 77 K to 9.5 G at 327 K.