Packing orientation

Yoon, Smith, and Matsuda, on the other hand, compared two approaches, using a united-atom model and a fully atomistic model.Stochastic dynamics and MD simulations of w-tridecane (C13H28) were used to study polyethylene. Besides studying the bulk melt, the authors examined confined melts between solid surfaces. Chain conformations, chain packing orientational correlations, and self-diffusion were among the properties studied. In regard to chain confer-... 

In conclusion, as already discussed in the case of alloy surfaces, Pd is retained in a stressed configuration, in registry with the substrate for close-packed orientations. On more open surfaces, Pd tends to relax the stress and reconstruct generating peculiar surface sites. In both cases, the chemical properties of surfaces are markedly modified. The mastery of the stress could be a way to tailor the catalytic properties of bimetallics. 

Odd versus even chain lengths were studied by Lin et al. [2002]. For alkyl trimethyl ammonium chloride/3-chlorobenzoate systems, lower Krafft temperatures and decreased lower drag-reducing temperatures were observed for odd-length chains than would be predicted from measurements with even chains. They attributed these effects to differences in nanostructure caused by differences in packing orientations in the micelle cores. 

S. D. Evans et al., Self-Assembled Mono-layers of Alkanethiols Containing a Polar Aromatic Group Effect of the Dipole Position on Molecular Packing, Orientation, and Surface Wetting Properties, J. Am. Chem. Soc. 1991, 113,4121-4131. 

Fig. 28 Crystal structure (left) and packing orientation right) of [12]CPP [41]...

Similarly, grain orientation on polished surfaces can affect the degree of etching. Close packed orientations can etch slighdy faster than lesser packed planes. 

The spectroscopic behavior observed for confined Si(OEt)3-ImPV-F (blue-shifted absorption, decreased intensity, and red-shifted emission) could be attributed to an H-type aggregation such an aggregation may reasonably be expected from a card pack orientation of the distyrylbenzene imide chromophores in the silicate network. The formation of the silyl network supports a face-to-face organization of chromophores. 

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