Energetic materials, structure synthesis

Materials synthesis is a necessary component in the development of advanced technologies for national security and homeland defense. For instance, new composites, nanoscale molecules and compounds, and polymers are needed for tougher, explosion- or puncture-resistant materials that can be employed in buildings, garments, bridges, and other products and structures. Personal protective materials could be enhanced with new chemical adsorbents filter materials, impermeable membranes, artificial sutures, and improved energetic materials for... 

There have been a number of investigations involving the study of nitroolefins as useful intermediates in the synthesis of energetic materials. A characteristic of many of them is a large twist about the double bond. Interest in the structural characteristics that accompany the rotation motivates a discussion of details. As would be expected, the rotation out of the normal planar conformation is associated with spatial crowding. Rgure 14 illustrates some of the largest out-of-plane rotations that have been measured and, in one case, calculated for crowded ethylenes [25j. 

Gas-phase nucleation Flame synthesis of particles (e.g., carbon black, silica) cluster formation in chemical vapor deposition manufacture of high-purity silicon cluster structure and energetics plasma synthesis of refractory materials and coatings. 

Zeolites are a subclass of microporous materials in which the crystalline inorganic framework is composed of four-coordinated species interconnected by two-coordinated species. Traditionally these materials are aluminosilicates however, many different compositions have been synthesized. The templates used in the synthesis of microporous materials are typically small ionic or neutral molecular species. The function of the template in the synthesis of microporous materials is little understood, and there are at least four different modes by which an additive can operate in a zeolite synthesis a) It may act as a space filler occupying the voids in the structure, thereby energetically stabilizing less dense inorganic framework b) the additive may control the equilibria in the synthesis mixture, such as solution pH or complexation equilibria c) it may preorganize the solution species to favor the nucleation of a specific structure d) it may act as a true template determining the size and the shape of the voids in the structure. 

There are mainly two reasons why so many GO structure models have been proposed in experiment. One reason is that GO samples vary from one batch to another under different synthesis conditions. Another reason is that assignment of spectroscopic data has been based on experiences on other molecules and materials and thus may not be very accurate. Theoretical studies are very useful in these two aspects. First-principles energetics can provide a clean simplified picture on GO structure, without the complexities of experimental conditions involved. On the other hand, computational spectroscopy provides a direct connection to experimental observations. 

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