Morphological evolution rapid

The mechanisms above allow rapid diffusional transport of atoms along the surface. We discuss the role of surface diffusion in the morphological evolution of surfaces and pores during sintering in Chapters 14 and 16, respectively. 

Fast and non-contact methods for the analysis of morphologies evolution during a fast process are highly attractive and, from this point of view, Ught transmission appears the more promising. In contrast to other methods (calorimetry. X-ray diffraction, densitometry), in fact, measurements of light intensity are very fast, economical, and can be applied in situations (rapid cooling, flow) when other methods are not adequate. 

Here is a brief description of the morphological evolution in the polymer blend from the moment it undergoes a rapid temperature jump from room temperature ( 25°C) to 135°C or 150°C when it is inserted into the preheated hot stage, and observed through the microscope. 

Breiner U, Krappe U et al (1996) Evolution of the knitting pattern morphology in ABC triblock copolymers. Macromol Rapid Commun 17 567-575... 

The astrophysical problem of justifying on theoretical grounds the morphology of galaxies (spiral and eUiptical, with their different content in stars and gas), their chemical evolution (initial rapid enrichment of metals, i.e., any element heavier than hydrogen and helium), and, finally, the attempt to trace a classification based on different physical aspects of the evolution, has been tackled by employing the approach of cooperative systems. In these models a scenario is proposed where the large-scale dynamics are related to the local microscopic interactions. At the same time a macroscopic description (e.g., the interplay of various phases, the metallicity) is derived by means of few (stochastic) variables. 

Well ordered mesoporous silicate films were prepared in supercritical carbon dioxide.[218] In the synthesis in aqueous or alcoholic solution, film morphology of preorganized surfactants on substrate cannot be fully prescribed before silica-framework formation, because structure evolution is coincident with precursor condensation. The rapid and efficient preparation of mesostructured metal oxides by the in situ condensation of metal oxides within preformed nonionic surfactants can be done in supercritical CCU- The synthesis procedure is as follows. A copolymer template is prepared by spin-coating from a solution containing a suitable acid catalyst. Upon drying and annealing to induce microphase separation and enhance order, the acid partitions into the hydrophilic domain of the template. The template is then exposed to a solution of metal alkoxide in humidified supercritical C02. The precursor diffuses into the template and condenses selectively within the acidic hydrophilic domain of the copolymer to form the incipient metal oxide network. The templates did not go into the C02 phase because their solubility is very low. The alcohol by-product of alkoxide condensation is extracted rapidly from the film into the C02 phase, which promotes rapid and extensive network condensation. Because the template and the metal oxide network form in discrete steps, it is possible to pattern the template via lithography or to orient the copolymer domains before the formation of the metal oxide network. 

Barz et found that stepping the potential to the region of rapid hydrogen evolution immediately prior to an ORC can result in a further enhancement of the SERS, by almost an order of magnitude as compared to an electrode subjected to ORC alone. They attribute this to an effect the presence of hydrogen bubbles on the electrode have on the surface morphologies created by the ORC. No identification of the precise structures was reported. 

When type 3 phase separation occurs (blends above 20.9 wt% TP), the evolution of complex viscosity is predominated by the (3-phase as it increases more rapidly from the beginning of phase separation (Figure 6c). The difference in this behavior is that the response of the a-phase is hidden by that of the (3-phase. Obviously, neither its contribution to the decrease in the global viscosity nor the gelation criterion is apparent. It is reasonable to say that the a-phase is dispersed in this case from the beginning of phase separation, and we propose a nucleation and growth mechanism with a phase inversion for this morphology. 

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