Crystal core-edge interaction

Planar condensed aromatic molecules are a particularly simple example, because their shapes are easy to describe, and the intermolecular potential is similar in different crystals [22]. Two basic interaction types emerge [23] a core-edge interaction. 

All the expressions given above for discli-nation and focal curve energies are similar to those for screw and edge dislocations in true crystals [9,15], but the situation is different for translation dislocations in smectics. The presence of a screw dislocation of weak Burgers vector does not introduce any splay and does not really modify the layer thickness even at small distances [16]. The energy is reduced to a core term and therefore interaction terms are absent in the frame of the linear theory. This is not the case for edge dislocations in this approximation [106], and one has the expression ... 

Fig. 8 Self-assembly aptitudes in the case of anisotropic hydrophobic interactions (R ethyl propyl, PEG refers to PEG17). Compound 1 forms segmented fibers, whereas 5 assembles into 2D crystals (as shown by cryo-TEM). Compound 6 can yield segmented fibers or crystals, depending on the self-assembly conditions. The interplay of interactions between the arranatic core and the alkyl edges drives the assembly, which can be further adjusted by adding an organic co-solvent (THE) [57]...

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