单壁纳米碳管（SWNT）电子衍射图模拟及螺旋角测量

自1991年Iijima发现碳纳米管以来，人们对碳纳米管的关注方兴未艾。利用透射电子显微镜对其结构进行研究，从实空间和倒空间表征其细节。其电子衍射图可测量并分析螺旋角。本工作通过用NCEMSS软件对各种类型的单壁纳米碳管(singlewalled nano-tube，SWNT)进行模拟，对得到的衍射图特     

纳米碳管的STM研究

本文应用扫描隧道显微镜对孤光放电方法得到的纳米碳管进行了观察。孤光放电法所产物的纳米碳管以直线型为主，并且多以束状存在。碳管束直径约２０ｎｍ，而单要碳管的直径大多在２ｎｍ到５ｎｍ之间。观察到单层碳秋的原子像，其表明为石墨网络的六角结构。纳米碳管的原子像及单极碳管表面均未发现明显缺陷存在，这可能是它具有很高强度质量比的主要原理之一。     

纳米碳管新用途：石棉纤维的屏蔽

本文报道了对石棉纤维外围生长的纳米碳管的观察和研究，利用电子显微镜可以看到，以直径为几十纳米的柱形石棉纤维表面为基可通过电弧放电的方法在石棉纤维表面生长屏蔽碳管，内部的石棉纤维及其外部的碳管均经过Ｘ射线能量损失谱的成份分析及选区电子衍射的结构分析加以证实。本文还对以石棉纤维为基体的碳管生长机制进行了探讨。     

纳米碳管制备方法及其微观形貌

制备纳米碳管的方法比较多，目前较常用的包托电孤放电法、气相沉积法（又称催化热解法）、激光蒸发法等。Yacamam等人采用铁和石墨颗粒作为催化剂，在常压，700℃条件下分解乙炔/氮气获得了纳米碳管，典型的催化热解法制备的纳米碳管，其微观形貌表现为碳管弯弯曲曲，较多转折。激光蒸发法获得的纳米碳管形貌介于电弧法和气相沉积法之间。     

纳米碳管催化热解方法的制备及其微观结构的研究

通过乙炔气体在纳米铁颗粒上的催化热解制备了纳米碳管。利用电子显微镜对纳米碳管的形貌和结构进行了观察研究。发现纳米碳管具有分支生长的可能性，研究了纳米碳管管壁发生局部弯折的机理。     

纳米碳管及一维纳米晶体结构研究

纳米碳管及基于纳米碳管的一维纳米晶体，由于其良好的应用前景而受到广泛重视。纳米碳管的电学特性单层纳米碳管由于其不同手性角，而显示半导体或金属电性［１—３］。本文对纳米管束进行了研究。ＪＥＭ－２０１０Ｆ及ＧａｔａｎＧＩＦ系统被用于管束的手性角测定及特征...     

纳米碳管对(Ni-P)化学复合镀的影响

讨论了采用化学复合镀技术制备纳米碳管-(Ni-P)复合镀层的工艺技术,研究了纳米碳管对(Ni-P)复合镀层耐磨性及抗腐蚀性的影响,确定了纳米碳管-(Ni-P)复合镀层的最佳工艺条件。同时还讨论了高温退火对镀层硬度的影响;并利用透射电镜观察纳米碳管的形貌,利用扫描电镜观察复合镀层的结构特点。     

纳米碳管周维的电位和电场分布

通过数值计算研究了单根碳管模型和碳管阵列模型下的电位和电场分布情况。利用有限差分求解碳管周围，特别是尖端附近的电位和电场分布。并通过修改模型参数，分析了碳管高度、碳管半径等几何参数对碳管周围电场分布的影响。对于碳管阵列模型还着重分析了碳管间的场屏蔽效应和场增强因子。     

精确测定碳纳米管螺旋度的电子衍射方法

本文介绍精确测定碳纳米管原子结构的电子衍射方法.电子衍射方法利用碳纳米管的电子衍射图与碳纳米管螺旋指数(u,v)间的内在关系,可以从(a)衍射层线上的电子散射强度分布或(b)衍射层线间距的比例测定碳纳米管的螺旋指数.电子衍射方法是迄今为止测定碳纳米管的螺旋指数的最有效方法.电子衍射方法除具有结果精度高外,亦可用于测定多层碳纳米管的每层的螺旋指数.     

纳米碳管及相关材料的电性能

碳管是Ｃ原子按一定的排列方式形成一封闭的结构，构成有别于金刚石和石墨的Ｃ的第三种分子形式。１９９１年日本发现了碳管的一种形式——纳米碳管。这类材料具有特殊的力学、化学、磁学、电学等性能。笔者综述纳米碳管及相关材料的电学性能及应用前景，指出这类材料近期有望在复合材料中得到应用，而运用到电子工业尚需较长的时间     

应力诱导碳纳米管电阻的变化

利用三点弯曲法研究了掺杂和末掺杂碳纳米管薄膜应力诱导电阻的变化。该研究中所用的碳纳米管是用热灯丝化学汽相沉积法合成的。实验结果表明 ,碳纳米管有显著的应力诱导电阻变化的效应。当应力从 0 .2GPa增加到 1GPa时 ,膜的电阻相对变化从 7%增加到 11% ,而非掺杂的薄膜电阻变化小于掺杂膜的情况。电阻随应力变化的原因也许是带隙变化 (掺杂 )和管之间接触电阻变化 (非掺杂 )所致     

Piezoresistive Sensors Based on Carbon Nanotube Films

Piezoresistive effect of carbon nanotube films was investigated by a three-point bending test. Carbon nanotubes were synthesized by hot filament chemical vapor deposition. The experimental results showed that the carbon nanotubes have a striking piezoresistive effect. The relative resistance was changed from 0 to 10.5 X 10-2 and 3.25 X 10-2 for doped and undoped films respectively at room temperature when the microstrain under stress from 0 to 500. The gauge factors for doped and undoped carbon nanotube films under 500 microstrain were about 220 and 67 at room temperature, respectively, exceeding that of polycrystalline silicon (30) at 35 ℃. The origin of the resistance changes in the films may be attributed to a strain-induced change in the band gap for the doped tubes and the defects for the undoped tubes.     

Carbon nanotube applications in microelectronics

The extraordinary characteristics of carbon nanotubes make them a promising candidate for applications in microelectronics. Catalyst-mediated chemical vapor deposition growth is very well suited for selective in-situ growth of nanotubes compatible with the requirements of microelectronics technology. This deposition method can be exploited for carbon nanotube vias. Semiconducting single-walled tubes can be successfully operated as carbon nanotube field effect transistors (CNTFET). A simulation of an ideal CNTFET is presented and compared with the requirements of the ITRS roadmap. Finally, we compare an upgraded CNTFET with the most advanced silicon metal oxide semiconductor field effect transistors and discuss integration issues.     

Localized states in metallic carbon nanotube systems

We have investigated the properties of purely metallic carbon nanotube systems made of a nanometer-size metallic island connected to another two metallic carbon nanotubes by means of topological defects. These structures present discrete energy levels, thus behaving as metallic quantum dots. When there is a symmetry gap between the matched tubes around the Fermi energy, the states are strongly localized in the central metallic section and completely uncoupled from the external nanotubes. Interestingly, we also find discrete states in structures made of metallic nanotubes without a common symmetry. In this case the states are actually resonances coupled to the leads continua.     

Amorphous Carbon Nanotubes with Tunable Properties via Template Wetting

Amorphous carbon nanotubes have been prepared by casting thin films of polyacrylonitrile (PAN) and polystyrene‐block‐polyacrylonitrile (PS‐b‐PAN) within a porous anodic aluminum oxide (AAO) membrane followed by pyrolysis. Raman and wide‐ angle X‐ray diffraction (WAXD) measurements indicate that the carbon nanotubes are of low crystallinity. The thickness of the carbon nanotube walls is controlled by either changing the concentration of the precursor solution or by using multiple casting and pyrolysis steps. When diblock copolymers of PS‐b‐PAN are used, it is found that nanopores are created within the nanotube walls after pyrolysis. The carbon nanotubes can be used to create carbon coated nanorods of polystyrene‐block‐polybutadiene (PS‐b‐PBD).     

Y-型纳米碳管的HRTEM研究

本文对Y-型纳米碳管的形貌和微观结构进行了HRTElVl表征,并探讨了其形成机理。结果表明：形成的Y-型纳米碳管内包裹Fe纳米微粒,管径分布在50—60nm之间;在反应中由于催化剂Fe纳米微粒粒径、形状和表面曲率不同,使纳米碳管在生长过程中产生分支,形成Y-型纳米碳管。     

Selective Enhancement of Inner Tube Photoluminescence in Filled Double‐Walled Carbon Nanotubes

A highly selective enhancement of the optical response of the inner tubes of double‐walled carbon nanotubes has been identified upon transformation of the residual C atoms inside the hollow core to linear carbon chains (LCC). By varying the growth conditions and using standardized suspensions, it has been observed that this optical response depends sensitively on the tube diameter and LCC growth yield. It is reported how the formation of LCC by postsynthesis annealing at 1400 °C leads to an increase of the photoluminescence (PL) signal of the inner tubes up to a factor of 6 for tubes with (8,3) chirality. This behavior can be attributed to a local charge transfer from the inner tubes to the carbon chains, counterbalancing quenching mechanisms induced by the outer tubes. These findings provide a viable pathway to enhance the low PL quantum yield of double‐walled carbon nanotubes and proof the capability of inner tubes to exhibit photoluminescence.     

化学处理增强碳纳米管的湿敏效应

研究了多壁碳纳米管的湿敏效应。研究中所用碳纳米管是用热灯丝化学汽相沉积法生长的。实验结果表明 ,经由化学修饰后碳纳米管的湿敏效应有了极大的增强。化学修饰后碳纳米管在水蒸汽中电阻相对变化达到了 30 0 % ,而未修饰只有 3.2 5 %。本文对其结果进行了分析和讨论     

Carbon Nanotube Alignment via Electrohydrodynamic Patterning of Nanocomposites

Electrohydrodynamic (EHD) pattern formation in carbon nanotube‐polymer composite films yields well‐defined patterns on the micrometer scale along with the alignment of carbon nanotubes (CNTs) within these patterns. Conductive pathways in nanotube networks formed during EHD patterning of nanocomposite films results in a substantial increase in the composites’ conductivity at loadings exceeding the percolation threshold. The degree of nanotube alignment can be tuned by adjusting the EHD parameters and the degree of alignment is mirrored by the conductivity across the film. Using etching techniques or by embedding relatively long nanotubes, patterned surfaces decorated by CNT brushes were generated.