Defect domain

Under electron irradiation (or by other mechanisms) it is possible to generate carbon vacancies leading to the formation of extended defect domains (with the presence of pentagonal and heptagonal, and even four-membered carbon rings) showing semiconductor character. This is the mechanism of formation of semiconductor properties in quantum-dot carbon nanoparticles or graphene nanoribbon. The mechanism... 

Let us assume that we have a facetted surface, or a surface with perfect and defect domains. The potential barrier that an electron has to surmount when leaving the solid through a defect region or through an open facet, for example of (110) orientation, is lower than that when the electrons pass through the (111) surface. The relevant quantity in chemisorption theory is not the averaged macroscopic work function, but rather is the work function of the site where a molecule adsorbs. We therefore define the local work function of a site as the difference between the potential of an electron just outside the surface dipole layer and the... 

So paracrystalline polymers are nearly identical with liquid-crystalline polymers, filled with amorphous defect domains. And network polymers or copolymers maybe compared with filled materials, cross links playing the same role as sub microscopic filler particles. 

Figure 7. EMPA X-ray energy spectrum of defect domain.

These different contrast mechanisms can all be used to reveal the scale of liquid crystalline polymer microstructures. In specimens that exhibit a mosaic texture, and in those that contain predominantly planar defects, domain size is easily defined in terms of areas that uniformly show extinction between crossed polars. However, if the defects are predominantly linear, as in specimens that exhibit schlieren textures, such simple characterization of microstructural scale is no longer possible. Here it is more convenient to look at the length of disclination line per unit volume, which is equivalent to the number of lines intersecting unit area, and analogous to the dislocation density as defined for crystalline solids. Good contrast is essential in order to obtain an accurate count. Technologically, microstructural scale is of growing interest because of its relevance to processability, mechanical properties and optical transparency. 

B. Zappone, C. Meyer, L. Bruno, E. Lacaze, Periodic lattices of frustrated focal conic defect domains in smectic liquid crystal films. Soft Matter 8, 4318 326 (2012)... 

In the process of hydrogen insertion into the carbon network, it seems that especially defective domains can adsorb hydrogen more preferably (Fig. 9.14). However, the filling of graphene layers through an intercalation phenomenon is still controversial. 

Fig. 5 Simulation of the compression of randomly situated monodisperse particles. The maximum surface coverage is lower than in perfect hexagonal order owing to the lattice defects. Domain structure formation can be observed...

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