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Case Studies in Material Selection and Substitution
Published in Mahmoud M. Farag, Materials and Process Selection for Engineering Design, 2020
The analysis shows that the PMMA–1 wt% MWNT gauge competes favorably with the commercially available metallic foil gauges. It is expected to become even more competitive as the cost of CNTs decreases with the progress of their development and the increase in their production volume. MWNTs are now available in kg quantities with purities reaching 99% and their prices in 2009 were 10 times cheaper than in 2009. The introduction of the catalytic chemical vapor deposition (CCVD) process allows industrial scale production of relatively low-cost MWNTs. In 2009, the price of CCVD MWNTs ranged from $500 to 1500 per kg. The use of SWNTs on an industrial large scale is expected to remain more limited as their price is more than 50 times the price of MWNTs. Such sensors can also be used as a conductive coating to measure strains over large areas. The CNT-based strain sensors have the added advantages that their strain sensitivity can be controlled by varying the CNT weight percent in the composite and that they can measure strain in all directions since the CNTs are randomly dispersed within the polymer matrix.
Nanocatalysts: A New “Dimension” for Nanoparticles?
Published in Claudia Altavilla, Enrico Ciliberto, Inorganic Nanoparticles: Synthesis, Applications, and Perspectives, 2017
Ciambelli Paolo, Sannino Diana, Sarno Maria
Carbon nanotubes are concentric graphitic cylinders, they can be multiwalled (MWNT) with a central tube of nanometric diameter surrounded by graphitic layers separated by about 0.34 nm, while single-walled nanotubes (SWNT) are constituted of only one graphitic layer. The first observed MWNTs were grown in an arc-discharge process, and two years later SWNTs were produced by the laser-ablation technique. During that time, the catalytic chemical vapor deposition (CCVD) method was first used to grow CNTs. CCVD immediately appeared as an effective way to the large-scale production of carbon nano-tubes, at lower cost, for some specific applications. As an example, the capability to grow CNTs directly on a substrate at a desired position (a great challenge from the technological point of view) and at lower temperatures than arc discharge or laser ablation allowed the CNT growth by CCVD to be integrated in the fabrication processes of microelectronic circuits (Cheng et al. 1998).
Principles and Methods for Integration of Carbon Nanotubes in Miniaturized Systems
Published in Anupama B. Kaul, Microelectronics to Nanoelectronics, 2017
A. John Hart, Sei Jin Park, Michael F.L. de Voider, Sameh H. Tawfick, Eric R. Meshot
Since the mid 1990s, catalytic chemical vapor deposition (CCVD or CVD) emerged as the most versatile and scalable method of CNT synthesis due to its low reaction temperatures (relative to arc, laser, and flame methods), high yield, and versatility for gas-phase (floating catalyst) or substrate-bound (fixed catalyst) growth (Dai, 2001; Teo et al., 2004; Terranova et al., 2006). Iijima found CNTs in the deposit on the carbon electrode of a DC electric arc (Iijima, 1991); this apparatus was very similar to that reported for synthesis of large quantities of C60 fullerenes (Kratschmer et al., 1990).
Modulation of silica layer properties by varying the granulometric state of tetraethyl orthosilicate precursor aerosols during combustion chemical vapor deposition (CCVD)
Published in Aerosol Science and Technology, 2020
Björn Sten Mark Kretzschmar, Paul Bergelt, Daniel Göhler, Fabian Firmbach, Ronny Köcher, Andreas Heft, Michael Stintz, Bernd Grünler
Combustion chemical vapor deposition (CCVD) is a cost-effective, large-scale coating method for a defined application of functional thin (nanoscaled) solid layers on substrates under atmospheric pressure. During CCVD, solid particles (i) are synthesized by flame pyrolysis of a precursor substance (gas, liquid) within an ignited combustion gas (e.g., butane-air or propane-air mixtures), (ii) are deposited on the substrate and (iii) form a disperse thin solid film. CCVD (Hunt, Carter, and Cochran 1993), which was developed primary for the purpose of adhesion promotion, is nowadays employed for applying anti-corrosion coatings, layers with increased transmission (for SiOx) (Zunke et al. 2014), semiconducting transparent layers (based on ZnO) (Zunke et al. 2013) or for reflecting noble metal layers (Struppert et al. 2010).
Calibration of nonlocal generalized helical beam model for free vibration analysis of coiled carbon nanotubes via molecular dynamics simulations
Published in Mechanics of Advanced Materials and Structures, 2023
Farshid Darvishi, Omid Rahmani
Catalytic chemical vapor deposition (CCVD) is a common technique used to synthesize CCNTs. Xie et al. [3] used the hot filament chemical vapor deposition (HFCVD) and microwave plasma chemical vapor deposition (MPCVD) techniques to prepare CCNTs. Figure 1 represents the transmission electron microscope (TEM) image of CCNTs’ morphology.