Nanotubes/nanowires

In general, nanotechnology MBBs are distinguished for their unique properties. They include, for example, graphite, fullerene molecules made of various numbers of carbon atoms (C60, C70, C76, C240, etc.), carbon nanotubes, nanowires, nanocrystals, amino acids, and diamondoids [97]. All these molecular building blocks are candidates for various applications in nanotechnology. 

There are more issues and complexity to be considered if various micro-electromechanical (MEMS)-type devices are included in the macroelectronics tool kit. As described previously, the materials and devices required for TFTs and circuits can provide adequate electromagnetic (visible and RF) sensitivity for many image-type applications. These materials may also provide satisfactory performance in pressure and strain sensors. Nanotube/nanowire-based devices look promising for various chem-bio sensors.85 However, there is little that is known about the ability to integrate printed microfluidic devices (and other such devices with moving parts) into a roll-to-roll-type process. 

Much of what is sold as nanotechnology is in fact a recasting of previous materials science, which is leading to a nanotech industry built solely on selling nanotubes, nanowires, and the like which will end up with a few suppliers selling low margin products in huge volumes . 

A whole new chemistry has been developed around this discovery, and the unusual properties have given rise to suggestions that it could be made into products for a superconducting material, a three-dimensional polymer, new catalysts, new materials with unusual electrical and optical properties and very high mechanical strength, sensors, nanotubes, nanowires, and so on. At this moment, there are, as yet, no products based on the fullerene on the market. 

In recent years much effort has been spent on the development of experimental techniques to grow well defined nanoscale materials, due to their possible applications in nanometric electronic devices. Indeed the creation of nanowire field effect transistors [128-132], nano-sensors [133,134], atomic scale light emitting diodes and lasers [135,136], has been made possible by the development of new techniques, which allow one to control the growth processes of nanotubes, nanowires and quantum dots. Of particular importance, among the different atomic scale systems experimentally studied, are... 

New spatial forms of carbon - fullerenes, nanotubes, nanowires and nanofibers attract significant interest since the time of their discovery due to their unique physicochemical and mechanical properties [1-3]. There are three basic methods of manufacturing of the carbon nanomaterials (CNM) - laser evaporation, electric arc process, and catalytic pyrolysis of hydrocarbons. However, the multi-stage manufacturing process is a serious disadvantage for all of them. For example, the use of organic solvents (benzol, toluene, etc.) for separation of fullerenes from graphite soot results in delay of the synthesis process and decrease in the final product quantity. Moreover, some environmental problems can arise at this. 

Finally, metal nanostructures were examined as new materials for ethylene epoxidation, which is in the form of silver nanoparticles, nanotubes, nanowires, nanocubes, and a silver-containing polyoxometallate (73,74). With the current popularity of nanotechnology in new materials, more of these systems are bound to be seen in the future. 

Think of a new device that you could fabricate by DPN that would be comprised of both nanoclusters and nanotubes/nanowires. What are some potential applications for this device ... 

Dozens of methods to synthesize nanotubes, nanowires, and nanorods have been reported that can be found in the references included in Table 1. In addition to the most well known ones, such as hot plasmas, laser ablation, chemical vapor deposition, high temperature solid state and hydrothermal synthesis, fill-ing/coating of carbon nanotubes and similar types of materials, three methods have been developed that enable the synthesis of a wealth of new anisotropic nanoparticles. 

Studies of nanochemical systems span many areas, from the study of the interactions of individual atoms and how to manipulate them, how to control chemical reactions at an atomic level, to the study of larger molecular assembhes, such as dendrimers, clusters, and polymers. From studies of assemblies, significant new structures—such as nanotubes, nanowires, three-dimensional molecular assembhes, and lab-on-a-chip devices for separations and biological research—have been developed. 

Fig. 24. TEM image of fully-filled tin nanotubes (nanowires) produced by electrolysis of graphite electrodes in SnClj and LiCl mixtures (0.5 99.5 by weight respectively)...

There are numerous examples in which nanostmetured materials have been used in hthium ion batteries. In the sections below we provide various examples according to the form of the material porous solids, nanoparticles, and nanotubes/nanowires. 

Other nanostrucmres that have been explored for electrochemical applications include nanotubes, nanowires, and nanorolls. These morphologies have provided important insight into how nanoscale stmctures affect the electrochemical behavior of materials. Described below are some case smdies that illustrate the influence of various parameters at nanoscale dimensions. 

T. J. Lee, and C.J. Lee, Fabrication and applications of conducting polymer nanotube, nanowire, nanohole, and double wall nanotube, Synth. Met., 153, 313-316 (2005). 

Joo J, Kim BH, Park DH, Sung JH, Choi HJ (2008) Conducting polymer nanotubes, nanowires, and nanocomposites synthesis, characteristics, and applications. In Nalwa HS (ed) Handbook of organic electronics and photonics, vol 1. American Scientific, California, pp 51-83... 

Gao, F. L., L. J. Zhang, and S. M. Huang. 2010. Fabrication horizontal ahgned M0O2/ single-waUed carbon nanotube nanowires for electrochemieal supereapacitor. Materials Letters 64 537—540. 

PANI is one of the promising materials in supercapacitors due to its high capacitive characteristics, low cost, and easy synthesis. The materials in nanosize form with high surface area and high porosity give the best performance as electrode materials for supercapacitors because of their distinctive characteristics of conducting pathways, surface interactions, and nanoscale dimensions. The synthesis and capacitive characterization of high-surface-area nanomaterials, that is, nanotubes, nanowires, etc., have been carried out extensively in the past decades. Consequently, different indirect methods were used to synthesize nanosized PANI, such as template synthesis, self-assembly, emulsions, and interfacial polymerization. ... 

FIGURE 16.4 I-V characteristics of iodine doped PA nanofiber. Znsef shows scanning force microscope image of PA nanofiber on top of Pt electrodes (with 100 nm separation). Typical diameter of PA nanofiber is 16-20 mn (From Park, J.G., et al. Synth. Met., 119, 53, 2001 and Park, J.G., Electrical transport properties of conducting polymer nanostructures Polyacetylene nanofiber, polypyrrole nanotube/nanowire, Ph.D. thesis, Seoul National University, Seoul, 2003.). 

Park, J.G. 2003. Electrical transport properties of conducting polymer nanostructures Polyacetylene nanofiber, polypyrrole nanotube/nanowire. Ph.D. thesis, Seoul National University, Seoul. 

Nanostructured materials, obtainable as fine powders, thin films or in bulk forms, often exhibit properties dramatically different from those of the same materials in larger more ordinary forms. The latter are often unknown in the case of cavity structures which are characteristic of the material itself. Nanostructures of other kinds, for example, nanotubes, nanowires or nanocrystals can be formed with metal phosphides (Chapter 8) and phosphorus nitrides (Chapter 4.5). 

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