碳纳米管的生长制备与应用

本文在以往研究的基础上记述并解析了电弧放电法、等离子体射流法和CVD法3种主要碳纳米管制备方法,对3种方法的优缺点进行了比较;针对纳米碳管的性质,对电学、力学和光学特性进行了分析;概括了碳纳米管现阶段的主要应用方面,并对碳纳米管应用的未来用途进行了展望。本文的研究为纳米碳管目前的发展做出总结,能在很大程度上促进纳米碳管的制造及应用的进一步发展。

宏观碳纳米管聚集体的力学性能及其在复合材料中的应用进展

碳纳米管具有优异的力、电、热、光学等功能特性,如何在宏观尺度上充分发挥和利用碳纳米管的优异性能是科学家和工程技术人员普遍关注的一个热点.宏观碳纳米管聚集体是推动碳纳米管应用研究发展的一个重要途径和手段.系统综述了碳纳米管纤维、碳纳米管薄膜以及碳纳米管阵列等宏观聚集体制备技术方面的最新研究进展,重点关注了聚集体的力学性能,并结合我们自身的研究工作,预测了碳纳米管聚集体在复合材料领域的应用和发展前景以及未米发展中可能的机遇和挑战.

Taguchi-Optimized Catalytic Growth of Carbon Nanotubes for Applications in Electro-Catalysis

Taguchi method, largely used to optimize processes controlled by manifold parameters, has been utilized to improve the synthesis of carbon nanotubes by chemical vapor deposition of isobutane. Analyzing results obtained in nine suitably designed reactions, the influence of synthesis （773-973 K）, calcinations （723-1,023 K） and reduction （773-973 K） temperatures and catalyst-support （alumina, magnesia or Na＋-exchanged K10 clay） on specific yield and crystallization degree （i.e., C sp2 content） of the nanotubes has been ranked. After critical examination and adjusting of conditions predicted to give optimal results, -50 g of nanotubes per gram of metal are obtained at 973 K over Fe/alumina catalysts calcined at 723 K and reduced at 773 K. Under the same conditions, highly crystallized nanotubes （with 73% of C sp2 bonds, as qualitatively estimated from Raman spectroscopy）, suitable for electro-catalysis applications, are synthesized over Fe/clay catalysts.

Impacts of Parameter Scaling for Low-Power Applications Using CNTFET （Carbon Nanotube Field Effect Transistor） Models： A Comparative Assessment

This paper provides an extension to the earlier work wherein a comparison between different models that had studied the effects of several parameters scaling on the performance of carbon nano tube field-effect transistors was presented. The evaluation for the studied models, with regard to the scaling effects, was to determine those which best reflect the very essence of carbon nano-tube technologies. Whereas the models subject this comparison （Fettoy, Roy, Stanford, and Southampton） were affected to varying degrees due to such parametric variations, the Stanford model was shown as still being valid for a wide range of chiralities and diameter sizes; a model that is also applicable for circuit simulations. In this paper, we present a comparative assessment of the various models subject to the study with regard to the effect of incorporating multiple carbon nanotubes in the channel region. We also assess the effect of oxide thickness on transistor performance in terms of the supply voltage threshold effects. Results leveraging our findings in this ongoing research endeavor reveal that many research efforts were not efficient to high degree due to high delay and not valid for circuit simulations.

Research on Polymer Materials in Bio Medical and Its Application

Intelligent hydrogels is as drug carrier, and it has a good application prospect. There are some changes factors in the human environment, such as temperature, pH. Therefore, the temperature sensitive hydrogels and pH sensitive hydrogels can release system for drugs in the body. So the paper detailed descript a novel MWCNTs good dispersion of PMAA/MWCNTs nano hybrid hydrogels. The introduction of MWCNTs significantly increased the hydrogel pH response and mechanical strength, and depends on the MWCNTs component ratio, particle size and concentration of cross-linking agent. The study found, swelling rate of hybrid hydrogels was faster than the pure PMAA hydrogel, and the swelling behavior were explained. The compression stress-strain experiments should be found, MWCNTs load transfer plays an important role in improving the mechanical properties of the hybrid hydrogels network compression.

Biological applications of carbon dots

Carbon dots （C-dots）, since their first discovery in 2004 by Scrivens et al. during purification of single-walled carbon nano- tubes, have gradually become a rising star in the fluorescent nanoparticles family, due to their strong fluorescence, resistance to pbotobleaching, low toxicity, along with their abundant and inexpensive nature. In the past decade, the procedures for prepar- ing C-dots have become increasingly versatile and facile, and their applications are being extended to a growing number of fields. In this review, we focused on introducing the biological applications of C-dots, hoping to expedite their translation to the clinic.

The structural,electronic and magnetic properties of the 3d TM(V,Cr,Mn,Fe,Co,Ni and Cu) doped ZnO nanotubes:A first-principles study

We have performed the first-principles calculations onto the structural,electronic and magnetic properties of seven 3d transition-metal(TM=V,Cr,Mn,Fe,Co,Ni and Cu) atom substituting cation Zn in both zigzag(10,0) and armchair(6,6) zinc oxide nanotubes(ZnONTs).The results show that there exists a structural distortion around 3d TM impurities with respect to the pristine ZnONTs.The magnetic moment increases for V-,Cr-doped ZnONTs and reaches maximum for Mn-doped ZnONTs,and then decreases for Fe-,Co-,Ni-and Cu-doped ZnONTs successively,which is consistent with the predicted trend of Hund's rule for maximizing the magnetic moments of the doped TM ions.However,the values of the magnetic moments are smaller than the predicted values of Hund's rule due to strong hybridization between p orbitals of the nearest neighbor O atoms of ZnONTs and d orbitals of the TM atoms.Furthermore,the Mn-,Fe-,Co-,Cu-doped(10,0) and(6,6) ZnONTs with half-metal and thus 100% spin polarization characters seem to be good candidates for spintronic applications.

Curved carbon nanotubes： From unique geometries to novel properties and peculiar applications

Incorporating pentagons and heptagons into the hexagonal networks of pristine carbon nanotubes （CNTs） can form various CNT-based nanostructures, as pentagons and heptagons will bend or twist the CNTs by introducing positive and negative curvature, respectively. Some typical so-made CNT-based nanostructures are reviewed in this article, including zero-dimensional toroidal CNTs, and one-dimensional kinked and coiled CNTs. Due to the presence of non-hexagonal rings and curved geometries, such nanostructures possess rather different structural, physical and chemical properties from their pristine CNT counterparts, which are reviewed comprehensively in this article. Additionally, their synthesis, modelling studies, and potential applications are discussed.

Tailoring the Diameter of Single-Walled Carbon Nanotubes for Optical Applications

Single-walled carbon nanotubes （SWCNTs） with specific diameters are required for various applications particularly in electronics and photonics, since the diameter is an essential characteristic determining their electronic and optical properties. In this work, the selective growth of SWCNTs with a certain mean diameter is achieved by the addition of appropriate amounts of CO2 mixed with the carbon source （CO） into the aerosol （floating catalyst） chemical vapor deposition reactor. The noticeable shift of the peaks in the absorption spectra reveals that the mean diameters of the as-deposited SWCNTs are efficiently altered from 1.2 to 1.9 nm with increasing CO2 concentration. It is believed that CO2 acts as an etching agent and can selectively etch small diameter tubes due to their highly curved carbon surfaces. Polymer-free as-deposited SWCNT films with the desired diameters are used as saturable absorbers after stamping onto a highly reflecting Ag-mirror using a simple dry-transfer technique. Sub-picosecond mode-locked fiber laser operations at -1.56μm and -2 μm are demonstrated, showing improvements in the performance after the optimization of the SWCNT properties.

Recent advances in flexible supercapacitors based on carbon nanotubes and graphene

Owing to the rapidly growing market for flexible electronics, there is an urgent demand to develop flexible energy storage devices. Flexible supercapacitors have received much attention due to their good flexibility, fast charge/discharge rate and long lifecycle times. Carbon nanotubes（CNTs） and graphene have good mechanical properties, which make them suitable for flexible supercapacitors. Based on different nanostructures of CNTs and graphene, we summarized the recent progress in CNTs-and graphene-based flexible supercapacitors with a brief description of the basic principles for evaluating their performance. Special emphasis was given to fabrication methods, capacitive performance and electrode configurations of different flexible supercapacitors.Furthermore, the remaining challenges and future research directions for CNTs-and graphene-based flexible supercapacitors have also been discussed.

Preparation of bilayer/three-layer PEO-carbon nanotube composite thin films and their toluene-sensing application

The bilayer poly(ethylene oxide)/multiple-walled carbon nanotubes(PEO/MWCNTs) and three-layer PEO/MWCNTs/PEO composite thin films were fabricated with the spraying process on the interdigitated transducers(IDTs) as gas sensors for toluene-sensing application.Compared with the bilayer thin film sensor,the sensor with three-layer thin films exhibited higher response values and better recovery property.The microstructures of sensing films were characterized by scanning electron microscopy(SEM) to indicate that the better sensing response of three-layer thin films might be ascribed to the sufficient adsorption of toluene molecules on the surfaces of upper and bottom PEO films.The selectivity of the three-layer film sensor was further investigated by comparing responses upon exposure to different interference vapors with the response to toluene exposure,and much higher response was observed in the case of toluene.Good repeatability of the three-layer film sensor was also observed.