Soft epitaxy

The adsorption of thiamin, riboflavin, and niacin, components of the B vitamin present in Aspilia Africana extract, was investigated [50]. Those molecules may adsorb through a soft epitaxy mechanism on the metal surface, with accommodation of the molecular backbone in characteristic epitaxial grooves on the metal surface (Fig. 5.3). 

FIGURE 5.3 Representative snapshots of the top views of thiamine, riboflavin and niacin on Al(l 10) surface, emphasizing the soft epitaxial adsorption mechanism. With permission fiom Mejeha et al. [50]. 

The onset of theoretical studies also suggests that the inhibition properties ate due to soft epitaxy adsorption and organic layer formation on the dense metal surfaces, whereas on stepped or nanocrystalline surfaces, such a homogeneous layer cannot be formed and molecules able to form a covalent bond with the surface will have better inhibition power. 

Numerous studies have indicated that CNTs can nucleate PSCs, and it was suggested that both isothermal and nonisothermal crystallization behavior can be used as a bellwether of CNT/polymer soft epitaxial matching for templated crystallinity. With the addition of CNT fillers into polymer matrices, some new properties (electrical conductivity, flame resistance) can be imparted, while others (mechanical strength, thermal conductivity) can be enhanced. Again, these properties are dependent on the interplay between CNT and polymer matrix, as well as the organization of the two. 

Yan C, Li H, Zhang J, Ozaki Y, Shen D, Yan D, Shi AC, Yan S. Surface-induced anisotropic chain ordering of polycaprolactone on oriented polyethylene substrate, epitaxy and soft epitaxy. Macromolecules 2006 39 8041-8048. 

Composites that associate various polymers, both crystalline and amorphous, and carbon nanotubes (CNT) are investigated in many laboratories. Improved mechanical and original electric properties have been reported. The interactions between crystalline polymers and CNT are difficult to decipher, given the small size of the latter. Work by Li and coworkers [77], based on electron microscopic observations, indicates that some form of soft epitaxy is involved. For CNT with a small... 

One of the more important applications of ion implantation is well engineering at relatively high ion energies. For the protection of dynamic random access memories from soft errors, different structures have been proposed and employed. The conventional procedure is to use epitaxial wafers well engineering beneath the active p- and n-channels provides a less expensive alternative. 

It is of some interest to consider the situation where one of the ideahzed 2D systems that have been addressed can be followed in a layer-by-layer growth mode from a strictly 2D plane to one that is more 3D like. Such is the situation in the formation of multilayer molecular films adsorbed to uniform substrates or where epitaxial metal or soft matter growth is realized in chemical vapor deposition, molecular beam epitaxy or polymeric deposition systems. The hneshape discussion above has to be modified to account for the development of the third dimension of order in the system. Conceptually this is rather straightforward. Instead of considering, as Warren did, an ideal 2D reciprocal lattice composed of an ordered array of uniform rods, the reciprocal lattice for an idealized multilayer (e.g., two to five individual layers) system is characterized by... 

In the reduction of NO by CO at low temperature, on Pd/MgO(100) model catalysts, the reaction rate is independent of CO pressure but increases with NO pressure [64,65], then the TON of the reaction is modified by the reverse-spillover effect and, in particular, depends on particle size. In that case, it is no longer possible to compare the TON value measured on different particle sizes, it is more appropriated to calculate the reaction probability [64], which takes into account for the real flux of molecules that reach the clusters which can be measured by molecular beam experiments. Reverse-spillover effects have also been recently observed for the CO oxidation on size-selected Pd clusters soft-landed on MgO epitaxial films [66]. 

Fig.l a Schematic view of the ferroelectric capacitor considered in [87], The epitaxy on SrTiOs is effectively taken into account by choosing the appropriate lattice parameter in the direction parallel to the interfaces, b Evolution of the energy as a function of the soft-mode I for different thickness of the ferroelectric film m. Symbols stand for the first principles results and lines present the results of a simpUfied electrostatic model. Reproduced with permission from [87]... 

Figure 12.29 Schematic representation of epitaxially oriented cross-hatched lamellar structure, in which the mechanically soft amorphous inter-lamellar regions of one phase are bridged by the crystalline lamellae of the other phase. Lotz and Wittmann [94]. Reproduced with permission of American Chemical Society.

Grosso, D., Rodriguez-Carvajal, J., and Sanchez, C. (2013) Soft-chemistry—based routes to epitaxial a-quartz thin films with tunable textures. Science, 340 (6134),... 

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