Multiwall carbon nanotubes MWCNTs

Multiwall carbon nanotubes (MWCNTs) have been synthesized by catalytic chemical vapor deposition (CCVD) of ethylene on several mesoporous aluminosilicates impregnated with iron. The aluminosilicates were synthesized by sol-gel method optimizing the Si/Al ratios from 6 to 80. The catalysts are characterized by nitrogen adsorption, X-ray diffraction, 27A1 NMR, thermogravimetric analysis (TGA) and infrared. The MWCNTs are characterized by TGA and transmission and scanning electron microscope. 

J.H.T. Luong, S. Hrapovic, and D. Wang, Multiwall carbon nanotube (MWCNT) based electrochemical biosensors for mediatorless detection of putresdne. Electroanalysis 17, 47—53 (2005). 

Multivariate curve resolution, 6 54—56 Multivariate linear regression, 6 32—35 Multivariate optical elements (MOE), 6 68 Multiwalled carbon nanotubes (MWCNTs), 77 48, 49 22 720 26 737. See also Carbon nanotubes (CNTs) Multiwall nanotubes (MWNTs) synthesis of, 26 806 Multiwall fullerenes, 12 231 Multiwall nanotubes (MWNTs), 12 232 Multiwall paper bags, 78 11 Multiway analysis, 6 57-63 Multiyear profitability analysis, 9 535-537 Multiyear venture analysis, 0 537-544 sample, 9 542-S44 Mummification, 5 749 Mumps vaccine, 25 490 491 Mumps virus, 3 137 Municipal biosolids, as biomass, 3 684 Municipal distribution, potential for saline water use in, 26 55-56 Municipal effluents, disposal of, 26 54 Municipal landfill leachate, chemicals found in, 25 876t... 

D. H. Zhang, M. A. Kandadai, J. Cech, S. Roth, S. A. Curran, Poly(L-lactide) (PLLA)/multiwalled carbon nanotube (MWCNT) composite Characterization and biocompatibility evaluation, Journal of Physical Chemistry B, vol. 110, pp. 12910-12915, 2006. 

George and Bhowmick [147] have also studied the influence of the polarity of EVA (40, 50, 60, and 70% vinyl acetate content) and the nature of the nanofiller [expanded graphite (EG), multiwall carbon nanotubes (MWCNTs), and CNFs] on the mechanical properties of EVA/carbon nanofiller nanocomposites. They pointed out that the enhancement in mechanical properties with the addition of various... 

Some potentially relevant work concerns the attachment of magnesium hydroxide nanoparticles onto multiwall carbon nanotubes (MWCNTs).92 These were prepared from water-in-oil emulsions specifically for conversion into MgO to functionalize and preserve the mechanical and the electrical properties of the CNTs, although not for fire-retardant purposes. However, although more speculative, this work may be of interest as it has been reported that combinations of M WCNT and micron-sized particles of ATH in EVA function as very efficient fire retardants through enhanced char formation and coherency.93... 

The most common method for the production of carbon nanotubes is hydrocarbon-based chemical vapor deposition (CVD) [97] and adaptations of the CVD process [98, 99], where the nanotubes are formed by the dissolution of elemental carbon into metal nanoclusters followed by precipitation into nanotubes [100]. The CVD method is used to produce multiwalled carbon nanotubes (MWCNTs) [101] and double-walled carbon nanotubes (DWCNTs) [102] as well as SWCNTs [103], The biomedical applications of CNTs have been made possible through surface functionalization of CNTs, which has led to drug and vaccine delivery applications [104,105],... 

The surface-enhanced Raman scattering (SERS)-active substrates were prepared by electrodeposition of Ag nanoparticles in multiwalled carbon nanotubes (MWCNTs)-based nanocomposites for SERS sensor application. 

An interesting experiment was performed to deposit Sn02 on multiwalled carbon nanotubes (MWCNTs) by CVD at 550 °C, using SnH4 as the tin source.42 This technique may provide a good way to produce tunable Sn02-MWCNT composites (Figure 3.1.4). 

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... 

Carbon nanotubes, generally in the form of multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs), may exhibit specific adsorption and electronic properties in comparison with activated carbon, due primarily to their peculiar morphology, the role of defects, the probability of opening or closing of the tubes, and so on [5], which are believed to induce cooperative or synergetic interactions between metal or metal oxide... 

Multiwall carbon nanotubes (MWCNT) were distributed in a magnesium alloy. 

Figure 7.3 Label-free voltammetry of 10 nM IgE on a multiwalled carbon nanotube (MWCNT)-modified screen-printed carbon electrode (solid line) and on a bare screen-printed carbon electrode (dashed line). Experimental conditions for differential pulse voltammetry were as described in Figure 7.2. MWCNTs (1 mg) were dispersed with the aid of ultrasonic agitation in 10 mL of N, Ai-dimethylformamide to give a 0.1-mg mL black solution. MWCNT film was prepared by pipetting a 2- xL drop of MWCNT solution onto the carbon working electrode of the screen-printed electrode and then evaporating the solvent at room temperature.

Supramolecular interactions were also utilized in synthesis of carbon nanotube/poly-propylene composites (see chapter Applications of Ball Milling in Nanocarbon Material Synthesis). Solid-state grafting of maleated polypropylene on the surface of multiwalled carbon nanotubes (MWCNTs) employs interactions of carbonyl and carboxyl groups with maleic anhydride groups via hydrogen bonds or other dipole-dipole interactions [8]. 

Other nano-fillers have also investigated. Cao et al. [253] reported the utilization of multiwalled carbon nanotubes (MWCNTs) as filler-reinforcement to improve the performance of plasticized starch (PS). The PS/MWCNTs nanocomposites were prepared by a simple method of solution casting and evaporation. The results indicated that the MWCNTs dispersed homogeneously in the PS matrix and formed strong hydrogen bonding with PS molecules. Besides the improvement of mechanical properties, the incorporation of MWCNTs into the PS matrix also led to a decrease in the water sensitivity of the PS-based materials. 

Multiwalled carbon nanotube (MWCNT) (Chengdu Organic Chemicals Co. Ltd., China) [98]... 

Research on fullerenes carried out at NEC Corporation (Japan) and at IBM (United States) led in 1991 to the isolation of fibrous clusters of single-walled carbon nanotubes (SWCNTs) (Figure 11.6). SWCNTs have since been joined by multiwalled carbon nanotubes (MWCNTs) (Figure 11.7) as well as nanotubes containing elements other than carbon. 

As compared to SWCNTs, the properties of capacitors based on double-wall carbon nanotubes (DWCNTs) were not published so frequently, as pure DWCNTs are very hard to obtain. Basically, DWCNTs and multiwall carbon nanotubes (MWCNTs) have a lower surface area for EDL formation as compared to SWCNTs. On the other hand, a variety of works on capacitive performance of MWCNTs has been published, as they are relatively easily synthesized and are much cheaper than SWCNTs. As dependent on the methods of synthesis and modifications, different types of MWCNTs with different specific surface area values were obtained. Their specific capacitance values obtained in aqueous and nonaqueous electrolytes are from 10 to 100 F/g. However, they are not so high as in the case of ACs. On the other hand, one must point out that bulk capacitance is relatively high because of high bulk density of MWCNTs. Synthesis of MWCNTs is often carried out by pyrolysis of ethylene using catalysts, for example, Fe-Co. 

Hydroxyapatite (CajQ(P04)g(0H)2) has also attracted considerable interest as a catalyst support. In these materials, wherein Ca sites are surrounded by P04 tetrahedra, the introduction of transition metal cations such as Pd into the apatite framework can generate stable monomeric phosphate complexes that are efficient for aerobic selox catalysis [99]. Carbon-derived supports have also been utihzed for this chemistry, and are particularly interesting because of the ease of precious metal recovery from spent catalysts simply by combustion of the support. Carbon nanotubes (CNTs) have received considerable attention in this latter regard because of their superior gas adsorption capacity. Palladium nanoparticles anchored on multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) show better selectivity and activity for aerobic selox of benzyl and cinnamyl alcohols [100, 101] compared to activated carbon. Interestingly, Pd supported on MWCNTs showed higher selectivity toward benzaldehyde, whereas activated carbon was found to be a better support in cinnamyl alcohol oxidation. Functionalized polyethylene glycol (PEG) has also been employed successfully as a water-soluble, low-cost, recoverable, non-toxic, and non-volatile support with which to anchor nanoparticulate Pd for selox catalysis of benzyl/cinnamyl alcohols and 2-octanol [102-104]. 

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