Dispersion post-treatment processes

It is evident that a highly dispersed CuCl catalyst will combine better with silicon and the Cu will diffuse faster into the Si lattice in the subsequent reaction steps. However, most works on this aspect have focused on the post treatment of a ready-made catalyst, which is a complicated process using a large amount of energy. 

The described methods of nanoparticle addition to the fibers (i.e., electrospinning of inorganic dispersions in polymer solutions, post-treatments, and sol-gel processes) determine in most cases an even distribution of the additive throughout the whole fiber section. This makes a firaction of particles ineffective when their function can be executed only in contact with the external environment. When nanoparticles are introduced into the nonwoven structure through electrospraying, they are completely and readily available for active reactions with the outside. 

Recently in the field of physics of semiconductors and materials science a great attention has been paid to formation and optical properties of semiconductor nanocrystals (quantum dots, QDs) dispersed in inorganic matrixes. An interest to glassy materials with QDs is associated with their unique physical properties and possibility to create elements of optoelectronic devices. Phase separation processes followed by crystallization are the basic in production of such materials. They result in formation of semiconductor nanocrystals stabilized within a glass matrix. The materials are advanced for various applications because of optical and thermal stability and possibility to control optical features through the technology of glass preparation and post-synthesis thermal treatment. 

When the blends are immiscible in the molten state, the crystallinity is even more complex function of the ingredients properties, com-patibilization method, processing parameters, and post-processing treatments. The following factors have been identified to play major role (i) molecular constitution and M of the components (ii) composition, (iii) the type of phase morphology and the degree of dispersion (iv) the interphase, thus interactions between the phases, nature of the interface, migration of nuclei from one phase to the other, etc. (v) melt history, in... 

Defects of other types at scales quite different from that of the unit cell can also be important. The surfaee stmeture represents both the crystal face during growth and the first structure presented to adsorbing molecules, so that surface study, for example by AFM and HRTEM, can give important clues to these processes. Furthermore, the structure of mesopores generated by post-synthetic treatment, or the size and dispersion of metal particles in bifunctional catalysts are both examples of non-periodic features important in catalysis, so that recently developed 3D TEM methods to study them have particular significance. 

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