Multi-walled nanotube, MWNT

Since their first discovery by Iijima in 1991 [1], carbon nanotubes have attracted a great deal of interest due to their very exciting properties. Their structure is characterized by cylindrically shaped enclosed graphene layers that can form co-axially stacked multi-wall nanotubes (MWNTs) or single-walled nanotubes (SWNTs). Like in graphite, carbon atoms are strongly bonded to each other in the curved honeycomb network but have much weaker Van der Waals-type interaction with carbons belonging to... 

Carbon nanotubes can have one, two, or many sidewalls and are referred to as single-, double-, or multi-walled nanotubes (SWNT, DWNT, or MWNT). Nanotubes can be metallic, or semi-conducting depending on the chirality of the tube. Single-walled nanotubes (SWNT) are about 1 nm in diameter, and hundreds of nanometers long, whereas multi-walled nanotubes (MWNT) are like nested... 

The filler route has proved to be very efficient to obtain isotropic composites with relatively large improvements in matrix properties at small mass (volume) fractions of nanocarbon. For example, electrical percolation in epoxy has been obtained with only 0.0025 wt% of multi-wall nanotubes (MWNTs) [12]. Similarly, a 2.7-fold increase in matrix modulus has been observed on addition of 0.6 vol% MWNTs to polyvinyl alcohol (PVA) [13]. Although more modest compared to the previous two examples, a... 

For nanomaterials this is especially true if the exposure scenarios used in the test system are not representative of those likely to be found in the field [91, 92]. For example, the degree of toxicity observed in aquatic invertebrates exposed to multi-walled nanotubes (MWNTs) in water and sediment was influenced by the functional groups on the MWNTs and their preparation for dispersal into the test systems [93]. As noted, even the concept of what constitutes nanomaterials is not fixed [87], so these emerging materials will likely require a rethinking of how their toxicity is assessed and the hazards and risks they might pose to ecosystems [90]. For more information on nanomaterials, including application of life-cycle concepts to their design, see Chapter 8. 

A functionalized carbon multi-walled nanotube, MWNT, was prepared in 2 steps by initially oxidizing the unfunctionalized nanotube with mixed acids followed by amida-tion with guanidine. When reacted with polystyrene-g-dibenzo-18-crown-6-ether, the polymer, polystyrene-g-dibenzo-18-crown-6-ether-g-(nanotube-g-guanidine), was formed having the nanotube component aligned perpendicular to the polystyrene backbone. 

Kim K-L, Kang H-Y, Lee J-C et al (2009) Fabrication of a multi-walled nanotube (MWNT) ionic liquid electrode and its application for sensing phenolics in red wines. Sensors 9 6701-6714... 

The elastic modulus is - 1 TPa for single-walled nanotubes (SWNT) and 0.3- 1 TPa for multi-walled nanotubes (MWNT). 

The CNTs, both single-walled nanotubes (SWNT) and multi-walled nanotubes (MWNT) prepared by chemical vapor deposition (CVD) and arc-discharge (AD) methods, respectively, were purchased from Iljin Nanotech, Co., Korea. For proton and electron irradiation experiments, CNTs sheets were prepared as shown in Figure 2 by filtration of the CNT solution mixed in dimethylformamide through a cellulose membrane (pore size 0.45 pm). The thickness of the CNT sheets was approximately 0.5 mm, and they were 47 mm in diameter. After drying in a vacuum oven at 80 °C for 24 hours, CNT sheets (Figure 2) were obtained. These sheets were used in the radiation experiments, and were used for analysis such as SEM, Raman spectroscopy and XPS without any further treatment. For a dispersion test, a CNT powder was used instead of the CNT sheets. 

Multi-walled nanotubes (MWNT) consist of several concentric graphene tubes, which its interlayer distance is around 3.4 A close to the distance between graphene layers in graphite. Its single shells in MWNTs can be... 

Although carbon nanotubes (CNTs) have been recently discovered [9], they have been attracting a great deal of scientific interest due to their potential application in areas such as adsorbents and composite materials. CNTs have die number of graphite sheets in tube walls can vary from 1 for single-walled nanotubes (SWNTs) to over SO for multi-walled nanotubes (MWNTs), and inner diameter raging from Inm to Snm with a definite diameter [1,3]. The possibility of controllable pore size and distribution sug sts that CNTs mi t be used applications such as gas storage and selective separations from gas mixtures. 

Figure 12. Population density (A) and adhesion area (B) of osteoblast-like MG 63 cells on day 2 after seeding on tissue culture polystyrene dish (TCPS). carbon fibrereinforced carbon composites (CFRC) and CFRC coated with a fullerene layer (CFRC+full). C Growth curves of MG 63 cells on a terpolymer of polytetrafluoroethylene. poljcvinyldifluoride and polypropylene (Ter), terpolymer mixed with 4 wt. % of single-wall carbon nanohorns (SWNH) or 4 wt.% of high crystalline electric arc multi-wall nanotubes (MWNT-A). D Growth curves of MG 63 cells on TCPS. a nanostructured diamond layer (Nano) and a layer with hierarchically organized micro-and nanostructure (Micro-Nano). Mean S.E.M. from 4-12 measurements. ANOVA. Student-Newman-Keuls method. Statistical significance TCPS. CFRC. Ter p<0.05 compared to the values on tissue culture polystyrene, pure CFRC and pure terpolymer [23].

Carbon nanotubes (CNT) consist of molecular cylinders of pure, hexag-onally-arranged carbon atoms with a diameter of a few nanometres and a length of many microns. They occur in two main forms the single-wall carbon nanotube (SWNT) composed of a single lattice cylinder of carbon, and the multi-wall nanotube (MWNT) version, consisting of concentric lattice cylinders of carbon they resemble one cylinder within another. The ends of the tubes are usually closed off by a carbon end-cap, also in lattice form. 

Carbon nanotubes (CNT) are nanostructured materials with superior mechanical, thermal and electrical properties. They can be classed as single-walled nanotubes (SWNT) or multi-walled nanotubes (MWNT). The SWNT can be thought of as a one-atom-thick layer of graphite, whereas MWNT as multiple concentric rolled layers of carbon atoms. They are highly useful in contributing to the properties of nanoscale structures. Levi et al. (2004) have investigated the properties of aPVDF-CNT matrix. They used both SWNT and MWNT and claimed that the piezoelectric and pyroelectric behaviours were enhanced remarkably over their parent polymer. 

SYNTHESIS OF YTTRIA STABILIZED ZIRCONIA (3YTZP) - MULTI-WALLED NANOTUBE (MWNTs) NANOCOMPOSITE BY DIRECT IN-SITU GROWTH OF MWNTs ON ZIRCONIA PARTICLES... 

A few studies concerning the reduction of carbon nanotubes, both single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs), have been reported. Charging SWNTs makes it possible to modify their conductive nature by tuning their Fermi level, as shown by Petit [18]. The reduction of the SWNTs, e.g. n-... 

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