Epitaxial Crystallization of Polymers

Epitaxially grown thin films of vapor-deposited organic compounds and defect structures in these films have been studied by electron diffraction and high-resolution imaging with TEM [23]. Here, epitaxial crystallization of polymers is briefly described. 

Epitaxial crystallization of polymers has been investigated for a wide variety of substrates minerals (alkali halides, talc, mica, and so on), low molecular weight organic materials (condensed and linear aromatics, benzoic acid and many of its substituted variants and their salts or hemiacids, other organic molecules of different types), and other crystalline polymers. 

Wittmann JC, Lotz B (1990) Epitaxial crystallization of polymers on organic and polymeric substrates. Prog Polym Sci 15 909... 

Wittmann, J., Hodge, A., Lotz, B., 1983. Epitaxial crystallization of polymers onto benzoic acid ... 

Control of the chain orientation As the epitaxial crystallization is based on the crystallographic matches between the overgrowing and substrate crystals, the epitaxial crystallization of polymers can only be achieved with the side... 

Epitaxial crystallization of polymers conforms to these rules, but adds a number of significant original features. These features stem mostly from the long chain nature of polymers, in which one crystallographic direction (along the chain, with its covalent bonds) differs signihcantly from the interchain directions. 

The correct analysis of epitaxial crystallization of polymers cannot merely rely on global investigation techniques. Whereas the latter are suitable for screening, epitaxy takes place at a very different length scale, namely at the unit-cell level. It is therefore mandatory to use techniques that can read the molecular organization at a local scale. Moreover, in case a metastable crystal form is produced, the impact of epitaxy may be lost beyond only a few nanometers away from the interface. This contribution has developed some of... 

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