Lattice planes, carbons

Electron diffraction analysis for these carbon tubes revealed that the tube wall consists of cylindrically stacked carbon layers. The lattice image for the carbon tubes with a diameter of 30 nm is shown in Figure 10.1.7, where at least four tubes cross each other. The thickness of the walls is about 10 nm, and consequently the carbon has a hollow with a diameter as small as 10 nm. Many small lines, which correspond to 002 lattice planes, are observed in the cross section of the walls for each tube. 

Fig. 9.8. High-resolution TEM micrograph of fishbone type carbon fibre. Note the graphite lattice planes with distances in between of 0.34 nm [Courtesy J.W. Geus].

XPS and FT-IR were used to characterize the modified CNT surfaces. The combined results provided quantitative information on the chemical composition and structure of CNTs. For XPS, when an X-ray beam is directed at the SWNT surface, the energy of the X-ray photon is absorbed by a carbon core electron. The core electron escapes from the atom if the photon energy is sufficiently large. Since CNTs are made up of a hexagonal lattice of carbon atoms analogous to die atomic planes of graphite, one can easily obtain the main peak at 285 eV from Cls. However, die raw material usually contains amorphous carbon and various... 

A thermal treatment of different carbon forms can lead to the formation of onionlike species as well. As for diamond particles, their surface structure plays an important role for the actual outcome of the process. If it is covered with functional groups, the bonding sites are saturated which renders a graphitization more difficult From danghng bonds, on the other hand, graphitized domains will arise that can serve as nucleation center to the formation of carbon onions. In this process, a suitable orientation of lattice planes as well as a small particle size that... 

Figure 10.20 Graphite is used as a control to demonstrate the resolution capabilities of the Phillips 420 TEM. The periodic structure shown above represents the 3.354 A interplanar spacing of the graphite lattice. Each lattice plane has a thickness equivalent to one carbon atom, which is 1.7 A. The image has been averaged four times (0.33 sec exposure), normalized, scaled, and low pass filtered for subtraction of background noise (x 4,500,000).> >...

We have addressed the potential energy for a number of cases in the last sections (Sections 6.10-1 to 6.10-5). The analysis of the last two cases (i) a molecule and two parallel lattice planes and (ii) a molecule and two parallel slabs, are particularly useful for the study of adsorption of nonpolar molecules in slitshaped micropore solids, such as activated carbon. 

In Sections 6.10-2 to 6.10-5, we have dealt with cases of interaction between a species and a lattice plane, a slab, two parallel lattice planes and two parallel slabs. Here, we will extend to the case of two parallel lattice planes with sublayers underneath each lattice layer. This case represents the case of activated carbon where the walls of slit-shaped micropore are made of many lattice layers. Although real micropore configuration is more complex than this, this configuration is the closest to describe activated carbon micropore structure. Before we address molecular interacts with two lattice layers with sub-lattice layers underneath, we consider first the interaction between one atom or molecule with one lattice layer with sub-lattice layers. 

Fi. 4. A two-dimensional representation of the lamellar structure (or lurbosiraiic structure) of a carbon fiber. The cross-section of carbon fiber has essentially parallel basal planes in the skin region, but extensive folding of layer planes can be seen in the core region. It is thought that this extensive interlinking of lattice planes in the longitudinal direction is responsible for better eompre.ssive properties of carbon fiber than aramid fibers. 

The origin of the high capacitance of edge-plane carbon (70 pF cm" ) is somewhat mysterious, but may be due to a locally enhanced population of charge carriers inside the lattice edges. On the other hand, the surprisingly low-capacitance component of basal plane carbon (2 pF cm ) is almost certainly due to the presence of a space-charge capacitance (Cjf.) in series with the capacitance in solution ... 

Figure 12.1 Atomic force microscopy (AFM) amplitude image of sPP crystallized on an amorphous carbon surface at 125 °C. The inset presents the electron diffraction pattern of the single crystal, which indicates an upright chain orientation. The single layer of the crystal is about 15 nm in thickness. The observed transverse microcracks, are associated with an approximate order-of-magnitude higher thermal expansion coefficient between the (020) lattice planes than between their (200) counterparts. Reproduced with permission from [64], copyright 2011, American Chemical Society.

Fig. XVII-18. Contours of constant adsorption energy for a krypton atom over the basal plane of graphite. The carbon atoms are at the centers of the dotted triangular regions. The rhombuses show the unit cells for the graphite lattice and for the commensurate adatom lattice. (From Ref. 8. Reprinted with permission from American Chemical Society, copyright 1993.)...

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