碳纳米管的性能及应用

本文在概括碳纳米管的制备基础上,着重对其性能和应用做出了阐述,并对应用前景和存在的问题进行了介绍.     

Biomolecular modification of carbon nanotubes for studies of cell adhesion and migration

We report a strategy for tailoring and patterning carbon nanotubes (CNTs) for biospecific cell studies. We synthesized a new electroactive hydroquinone terminated pyrene molecule to tailor CNTs. These modified CNTs can be oxidized and chemoselectively reacted with oxyamine tethered ligands to generate various ligand tethered CNTs. A cell adhesive Arg-Gly-Asp peptide (RGD) is immobilized to the CNTs and a new microfluidic patterning method is employed to generate multiplex patterned surfaces for biospecific cell adhesion and migration studies. This work demonstrates the integration of a new functionalization strategy to immobilize a variety of ligands to CNTs for a range of potential drug delivery, tissue imaging and cellular behavior studies and a microfluidic patterning strategy for generating complex high-throughput surfaces for biotechnological and cell based assay applications.     

Soluble carbon nanotubes and their applications

Carbon nanotubes (CNTs) have been the forefront of nanoscience and nanotechnology due to their unique electrical and mechanical properties and specific functions. However, due to their poor solubility in solvents, the applications using the materials have been limited. Therefore, strategic approaches toward the solubilization of CNTs are important in wide fields including chemistry, physics, biochemistry, biology, pharmaceuticals, and medical sciences. In this article, we summarize: (i) the strategic approaches toward the solubilization of CNTs using chemical and physical modifications, (ii) nanocomposites of CNTs and biological molecules including DNA, (iii) formation of CNTs with topological structures, (iv) separation of metallic and semiconducting nanotubes, (v) the preparations of films and fibers of CNTs and hybrid materials of CNTs and organic and inorganic molecules.     

The physics and applications of carbon nanotubes

The discovery of carbon nanotubes in 1991 spurred an enormous worldwide research effort spanning the physical, chemical, and life sciences. This review will attempt to convey to the reader the unique physical attributes of carbon nanotubes and the range of possible applications.     

碳纳米管的改性与应用

本文主要介绍对碳纳米管不同位置的修饰以及其应用等方面的研究进展,并对今后的研究方向进行展望.     

Design of double-walled carbon nanotubes for biomedical applications

Double-walled carbon nanotubes (DWNTs) prepared by catalytic chemical vapour deposition were functionalized in such a way that they were optimally designed as a nano-vector for the delivery of small interfering RNA (siRNA), which is of great interest for biomedical research and drug development. DWNTs were initially oxidized and coated with a polypeptide (Poly(Lys:Phe)), which was then conjugated to thiol-modified siRNA using a heterobifunctional cross-linker. The obtained oxDWNT-siRNA was characterized by Raman spectroscopy inside and outside a biological environment (mammalian cells). Uptake of the custom-designed nanotubes was not associated with detectable biochemical perturbations in cultured cells, but transfection of cells with DWNTs loaded with siRNA targeting the green fluorescent protein (GFP) gene, serving as a model system, as well as with therapeutic siRNA targeting the survivin gene, led to a significant gene silencing effect, and in the latter case a resulting apoptotic effect in cancer cells.     

Nitrogen plasma functionalization of carbon nanotubes for supercapacitor applications

Surface modification of carbon nanotubes with a simple and fast plasma treatment allows for the design of new nanomaterials with enhanced electrochemical properties. Both structural disorder and nitrogen concentration of the nanotubes increase after a nitrogen plasma treatment. The effect of plasma power and nitrogen pressure on the charge storage capability of the nanotubes has been investigated in detail. Depending on the plasma conditions, nitrogen functionalities such as quaternary nitrogen in the basal planes, and pyrrolic groups at the edges are introduced in the nanotubes structure. The potential difference between anodic and cathodic peaks of the Fe³⁺/Fe²⁺ redox couple decreases from 102 mV down to 75.7 mV after the nitrogen plasma treatment, which accounts for an increased reversibility of the electron transfer process between nanotubes and electrolyte. Moreover, the treated nanotubes show a significant increase in their specific capacitance from 22 up to 55 F g^?1 at a scan rate of 10 mV s^?1 in a 0.1 M Na₂SO₄ solution. Pyridinic and pyrrolic functionalities are found to play an important role in enhancing the reversibility and specific capacitance of the obtained electrodes.     

Polydiacetylene single-walled carbon nanotubes nano-hybrid for cellular imaging applications

The functionalization of single-walled carbon nanotubes (SWCNTs) by forming self-assembled supramolecular structure of 10,12-pentacosadiynoic acid (PCDA) on the carbon nanotube wall is reported. PCDA assemblies on SWCNTs (PCDA/SWCNTs) were polymerized by UV irradiation to extensively conjugated polydiacetylene (PDA). PDA/SWCNT was identified by absorption and emission spectroscopy, scanning and transmission electron microscopies (SEM and TEM) and atomic force microscopy (AFM). PDA/SCWNTs showed strong near-infrared (NIR) fluorescence caused by fluorescence resonance energy transfer (FRET) between PDA network and semiconducting SWCNT core. The micro-patterning of biotinylated PDA/SWCNT with FITC-avidin on biotinylated glass surface demonstrated the potential application for a bio-sensing device. Furthermore, the biocompatibility for mammalian cancer cells was tested by viability experiments, which revealed that the PDA/SWCNTs had very low toxicity below 31.3 mg/L in terms of pristine SWCNTs concentration. Also, PDA/SWCNTs inside the cells can be observed by NIR microscopy. This unique modular method of preparation can contribute to diverse functionalities for practical applications in various non-invasive cellular imaging.     

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 ∼1.56 μm and ∼2 μm are demonstrated, showing improvements in the performance after the optimization of the SWCNT properties.      

Hybrid metal-based carbon nanotubes: Novel platform for multifunctional applications

Combining objects with diverse properties has often the advantage of giving rise to novel functionalities. In this scenario, metal-filled and decorated carbon nanotubes (m-CNTs) represent a class of hybrid carbon-based nanostructured materials with enormous interest for application in several fields, ranging from nanoelectronics and spintronics to nanomedicine and magnetic data recording. The present review will provide the reader with an overview of state-of-the-art hybrid architectures based on m-CNT systems, methods currently employed for their fabrication, the set of their unique properties and how they can be applied toward novel devices with multifunctional properties for a broad range of applications.     

Field-emission characteristics of carbon nanotubes and their applications in photonic devices

Based upon the field-emission investigation of carbon nanotubes, several prototype devices have been suggested that operate with low swing voltages with sufficiently high current densities. Characteristics that allow improved current stability and long operating lifetime as electrical and opto-electronic devices are presented. The aim of this paper is to illustrate the useful characteristics of carbon nanotubes and their possible applications.     

Printed multilayer superstructures of aligned single-walled carbon nanotubes for electronic applications

We developed means to form multilayer superstructures of large collections of single-walled carbon nanotubes (SWNTs) configured in horizontally aligned arrays, random networks, and complex geometries of arrays and networks on a wide range of substrates. The approach involves guided growth of SWNTs on crystalline and amorphous substrates followed by sequential, multiple step transfer of the resulting collections of tubes to target substrates, such as high-k thin dielectrics on silicon wafers, transparent plates of glass, cylindrical tubes and other curved surfaces, and thin, flexible sheets of plastic. Electrical measurements on dense, bilayer superstructures, including crossbars, random networks, and aligned arrays on networks of SWNTs reveal some important characteristics of representative systems. These and other layouts of SWNTs might find applications not only in electronics but also in areas such as optoelectronics, sensors, nanomechanical systems, and microfluidics.     

MoS2-modified nitrogen-doped carbon nanotubes and their applications in supercapacitors

Journal of Materials Science: Materials in Electronics - High-performance electrochemical energy storage device is an important means to solve the energy problem. As one of the next-generation...     

Modelling interwall interactions in carbon nanotubes: fundamentals and device applications

Carbon nanotubes are the most commonly used 'building blocks' of modern nanotechnology. Their unique mechanical and electronic properties, stability and functionality show great promise in creating functional devices on the nanometre scale. One of the great challenges in using this scale is the ability of physical manipulation of the components, such as their positioning and assembling. Strong correlation between the structure and mechanical interactions of the walls of carbon nanotubes provides self-regulation of their relative motion. This can be further exploited in low-friction and high-stiffness devices. In this paper, we present a condensed overview of the recent progress in fundamental understanding of nanomechanical and nanoelectromechanical behaviour of carbon nanotubes and their applications in nanodevices.     

Charge-transfer interaction in single-walled carbon nanotubes with tetrathiafulvalene and their applications

We observed that single-walled carbon nanotube (SWNT) was aligned in the presence of TTF This alignment was induced by a specific interaction between SWNT and tetrathiafulvalene (TTF), a well-known organic donor. The interaction between the two molecules can be explained by a charge-transfer, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The binding energies of S (2P1/2) and S (2P3/2) were shifted from 163.0 eV and 164.1 eV to 163.9 eV and 165.1 eV, respectively. In Raman spectra of the SWNT-TTF, three peaks of SWNT in radial breathing mode were also upshifted by 4-5 cm(-1). The charge-transfer interaction also contributed in modifying the electronic structure of SWNT and furthermore enhanced the electrical conductivity of SWNT. A more conductive thin film was fabricated using the SWNT-TTF Four-probe measurement revealed that the surface resistance of the SWNT-TTF film was reduced to 4.359 omega at room temperature while that of SWNT film was 6.894 omega. These results enable carbon nanotubes to be utilized more for practically for industrial applications in fabricating peculiar nano-sized building blocks.     

Development of multi-walled carbon nanotubes reinforced monetite bionanocomposite cements for orthopedic applications

In this study, we present results of our research on biodegradable monetite (DCPA, CaHPO₄) cement with surface-modified multi-walled carbon nanotubes (mMWCNTs) as potential bone defect repair material. The cement pastes showed desirable handling properties and possessed a suitable setting time for use in surgical setting. The incorporation of mMWCNTs shortened the setting time of DCPA and increased the compressive strength of DCPA cement from 11.09 ± 1.85 MPa to 21.56 ± 2.47 MPa. The cytocompatibility of the materials was investigated in vitro using the preosteoblast cell line MC3T3-E1. An increase of cell numbers was observed on both DCPA and DCPA-mMWCNTs. Scanning electron microscopy (SEM) results also revealed an obvious cell growth on the surface of the cements. Based on these results, DCPA-mMWCNTs composite cements can be considered as potential bone defect repair materials.     

Coumarin-conjugated multiwalled carbon nanotubes for potential biological applications: development and characterization

This work presents a novel cascade of chemical functionalization of multiwalled carbon nanotubes which allows the conjugation with differently substituted coumarins. Aim of the present work is to synthesize new materials able to rescue cells from the adverse effect of CNT particles since pristine CNTs are practically insoluble and tend to accumulate inside cells, organs and tissues. Moreover, it was reported that single walled CNTs particles show an adverse effect on keratinocytes through an oxidative mechanism, leading to NF-kB activation. The conjugation with coumarins, known superoxide anion scavengers, could switch the cytotoxicity of the new materials. The cascade functionalization of MWCNTs by sequential steps of carboxylation, acylation, amine modification and finally, coumarin conjugation have been performed and the synthesis and the chemical properties of several f-MWCNTs-coumarins have been exploited.     

Electric field-assisted deposition of nanowires on carbon nanotubes for nanoelectronics and sensor applications

Manipulation and control of matter at the nanoscale and atomic scale levels are crucial for the success of nanoscale sensors and actuators. The ability to control and synthesize multilayer structures using carbon nanotubes that will enable the building of electronic devices within a nanotube is still in its infancy. In this paper, we present results on selective electric field-assisted deposition of metals on carbon nanotubes realizing metallic nanowire structures. Silver and platinum nanowires have been fabricated using this approach for their applications in chemical sensing as catalytic materials to sniff toxic agents and in the area of biomedical nanotechnology for construction of artificial muscles. Electric field-assisted deposition allows the deposition of metals with a high degree of selectivity on carbon nanotubes by manipulating the charges on the surface of the nanotubes and forming electrostatic double-layer supercapacitors. Deposition of metals primarily occurred due to electrochemical reduction, electrophoresis, and electro-osmosis inside the walls of the nanotube. SEM and TEM investigations revealed silver and platinum nanowires between 10 nm and 100 nm in diameter. The present technique is versatile and enables the fabrication of a host of different types of metallic and semiconducting nanowires using carbon nanotube templates for nanoelectronics and a myriad of sensor applications.     

碳纳米管的偶联剂修饰及其在环氧树脂复合材料中的应用

为了在环氧树脂( EP) 复合材料中改善碳纳米管(CNTs) 的分散性和获得优良的界面特性, 利用Fenton 试剂对CNTs 进行了羟基化处理, 然后分别利用硅烷偶联剂KH550、KH560、KH570 和钛酸酯偶联剂NDZ201对羟基化CNTs 进行表面修饰, 通过SEM、TGA、DSC 和阻抗分析仪研究偶联剂修饰对CNTs/ EP 复合材料性能的影响。实验结果表明: Fenton 试剂和4 种偶联剂修饰都能显著改善CNTs 在复合材料中的分散性, 提高EP的玻璃化温度(T_g) 和热稳定性, 其中偶联剂修饰比Fenton 试剂处理更有效; 然而这些改性却大幅度降低了复合材料的导电性能、介电常数以及介电损耗。4 种偶联剂中, KH560 对应的复合材料的T_g最高, 热稳定性和导电性能最好, 同时具有较高的介电常数和较低的介电损耗。      

Random networks and aligned arrays of single-walled carbon nanotubes for electronic device applications

Singled-walled carbon nanotubes (SWNTs), in the form of ultrathin films of random networks, aligned arrays, or anything in between, provide an unusual type of electronic material that can be integrated into circuits in a conventional, scalable fashion. The electrical, mechanical, and optical properties of such films can, in certain cases, approach the remarkable characteristics of the individual SWNTs, thereby making them attractive for applications in electronics, sensors, and other systems. This review discusses the synthesis and assembly of SWNTs into thin film architectures of various types and provides examples of their use in digital electronic circuits with levels of integration approaching 100 transistors and in analog radio frequency (RF) systems with operating frequencies up to several gigahertz, including transistor radios in which SWNT transistors provide all of the active functionality. The results represent important steps in the development of an SWNT-based electronics technology that could find utility in areas such as flexible electronics, RF analog devices and others that might complement the capabilities of established systems. This article is published with open access at Springerlink.com