Thin coatings carbon nanotube composites

Nanocarbon hybrids have recently been introduced as a new class of multifunctional composite materials [18]. In these hybrids, the nanocarbon is coated by a polymer or by the inorganic material in the form of a thin amorphous, polycrystalline or single-crystalline film. The close proximity and similar size domain/volume fraction of the two phases within a nanocarbon hybrid introduce the interface as a powerful new parameter. Interfacial processes such as charge and energy transfer create synergistic effects that improve the properties of the individual components and even create new properties [19]. We recently developed a simple dry wrapping method to fabricate a special class of nanocarbon hybrid, W03 /carbon nanotube (CNT) coaxial cable structure (Fig. 17.2), in which W03 layers act as an electrochromic component while aligned... 

Multiwall carbon nanotube (MWCNT)-reinforced hydroxyapatite composite coatings (80% HAp/20% MWCNT) were deposited on austenitic stainless steel AISI 316L by laser surface alloying (LSA) with a 2.5-kW CW Nd YAG laser (Kwok, 2007). EIS of unprotected AISI 316L and HAp/MWCNT-coated steel obtained at open circuit potential are shown in Figure 7.60 after immersion in 0.9% NaCl solution for 2 h. The Bode plot shows that the total impedance Z has noticeably increased for the steel substrate coated with HAp/MWCNT. While the thin passive oxide film on the stainless steel surface was rendered less protective... 

For some applications, especially in the area of corrosion protection, electropolymerization of polyaniline onto active substrate is of interest. Lacroix and co-workers achieved this by first coating mild steel with a very thin PPy layer and then electrocoating polyaniline on top of this. Others have electrodeposited polyaniline-PPy composites on aluminum or steeP surfaces using oxalic acid electrolytes. A number of ring-substituted anilines have also been directly electrodeposited on active iron substrates using an oxalic acid electrolyte. To create novel nanostructures, polyanilines have been recently deposited on aligned carbon nanotubes or into the interstitial spaces of inverse opals to create novel ordered 3-D networks (Figure 4.2). Molecular templates (such as cyclodextrin) have also been added to electrode surfaces to facilitate electrodeposition of nanostructures. ... 

Flame-barrier coatings—Thin coatings composed of multi-walled carbon nanotubes dispersed in silicone matrices exhibit outstanding flame barrier characteristics (i.e., protection from combustion and decomposition). In addition, they offer abrasion and scratch resistance do not produce toxic gases and are extremely adherent to most glass, metal, wood, plastic, and composite surfaces. Hame-barrier coatings are used in aerospace, aviation, electronic, and industrial applications, and typically applied on wires and cables, foams, fuel tanks, and reinforced composites. 

Until now, the macroscopic tribological properties of the nanotubes had not been studied. The only studies carried out used the nanotubes as reinforcement in various matrices diamond thin film [87], polyimide [88], Ni [89], Ni-P [90], carbon/carbon composites [91] and alumina [92, 93]. These composite coatings present a better wear resistance and a lower friction. In nanotribology, Ohmae et al. studied friction of a gold tip on a nanotube forest. The friction coefficient obtained was high (1.2 to 1.5) and independent of humidity [94]. A very weak adhesion of the tip on the nanotubes was observed. During friction, no distortion of the nanotubes intervenes and there is no transfer of nanotubes on the tip. Recently, Miyoshi et al. 

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