Solid state chemical reaction

The general subject of solid-state chemical reaction in shock-wave compression, or shock-wave synthesis, has recently become an important part of the... 

In this chapter shock modification of powders (their specific area, x-ray diffraction lines, and point defects) measurements via analytical electron microscopy, magnetization and Mossbauer spectroscopy shock activation of catalysis, solution, solid-state chemical reactions, sintering, and structural transformations enhanced solid-state reactivity. 

Bell, L.N. and Hageman, M J. 1994. Differentiating between the effects of water activity and glass transition dependent mobility on a solid state chemical reaction Aspartame degradation. J. Agric. 

Experimental determination of Ay for a reaction requires the rate constant k to be determined at different pressures, k is obtained as a fit parameter by the reproduction of the experimental kinetic data with a suitable model. The data are the concentration of the reactants or of the products, or any other coordinate representing their concentration, as a function of time. The choice of a kinetic model for a solid-state chemical reaction is not trivial because many steps, having comparable rates, may be involved in making the kinetic law the superposition of the kinetics of all the different, and often unknown, processes. The evolution of the reaction should be analyzed considering all the fundamental aspects of condensed phase reactions and, in particular, beside the strictly chemical transformations, also the diffusion (transport of matter to and from the reaction center) and the nucleation processes. 

Certain solid phases, on the other hand, cannot be obtained (even as microcrystalline powders) by crystallization experiments, but instead can be generated only by other types of preparation procedure. Some types of preparation processes commonly (or in some cases inherently) yield microcrystaUine products, including (1) preparation of materials directly from solid-state chemical reactions (see Sect. 6.6), (2) preparation of materials by solid-state desolvation processes (see Sect. 6.4), (3) preparation of materials by solid-state grinding (mechanochemical) processes (see Sect. 6.2), and (4) preparation of materials directly by rapid precipitation from solution (as opposed to crystallization) (see Sect. 6.7). Again, structure determination from powder XRD data may represent the only opportunity for determining the structural properties of new solid phases obtained by such processes. 

Finally, the perturbed y-y angular correlation (PAC) nuclear method has been shown to register adequately with in-situ solid state chemical reactions, both on microscopic and macroscopic scales. The analysis of PAC is, in principle, more complicated than that of MS because two consecutive y-emissions and their correlation are involved in the spectroscopic process. 

Since intermolecular isotope effects were unprecedented in solid-state chemical reactions, a number of experiments were required to show that the results are reproducible and that differences could not be attributed to the history or condition of the crystals, the temperature or extent of photolysis, or differences in the orientation, coupling, absorptivity, or state of com-plexation of C02 dimers between labeled and unlabeled crystals. Success in excluding these alternative interpretations [5] underlines the power of the infrared method, and the special virtues of studying single crystals. 

Minimally, one should have a brief foreknowledge of the thermal and thermal/humidity solid-state stability of the API prior to initiation of excipient compatibility studies. These protocols should include investigation of stability at various temperature and humidity conditions and should always include information about both chemical stability and physical-form integrity of the API. Thermal and thermal moisture-induced solid-state chemical reactions are well known (5), with hydrolysis and oxidation being the most prevalent mechanisms of decay. Changes in physical form with thermal and... 

The monograph only contains the material which cannot be found in any other book, with the exception of two previous books Kinetics of Solid State Chemical Reactions (Naukova Dumka, Kiev, 1992, in Russian)... 

Nuclear Magnetic Resonance Imaging of Anisotropic Solid-State Chemical Reactions... 

I. M. Barkalov, V. V. Barelko, V. I. Goldanskii, D. P. Kiryukhin. and A. M. Zanin, Threshold Phenomena and Autowave Processes in Low-Temperature Solid-State Chemical Reactions , preprint, Inst. Chem. Physics AN SSSR, Chernogolovka (1983) (in Russian). 

The mineralogical phases formed by heating the clay-carbonate mixtures are summarized in Tables I and II. Solid-state chemical reactions at temperatures below fusion are rather common. 

Butler, L. G., Cory, D. G., Dooley, K. M., Miller, J. B. and Garroway, A. N. (1992). NMR imaging of anisotropic solid-state chemical-reactions using multiple-pulse line-narrowing techniques and H-1 T1-weighting. J. Am. Chem. Soc., 114, 125-35. [238]... 

This contribution gives a review of recent spectroscopic investigations concerning the photophysical and photochemical primary and secondary processes of the solid state polymerization reaction in diacetylene single crystals. It will be shown, that diacetylenes are an unique model system for the study of the reaction mechanism of a solid state chemical reaction which is characterized by a variety of reaction intermediates. The polymerization reaction in these crystals is of special importance, due to the resulting polymer single crystals, which exhibit extraordinary anisotropic physical properties. 

The kinetics of solid state chemical reactions are ordinarily limited by the rate at which reactant species are able to diffuse across phase boundaries and through intervening product layers. As a result, conventional solid state techniques for manufacturing ceramic materials invariably require the use of high processing temperatures to ensure that diffusion rates are maintained at a high level, thus allowing chemical reaction to proceed without undue kinetic constraint. ... 

Macrokinetie Peculiarities of Solid-State Chemical Reactions in the Region of Low-temperature Limit of Rate Constant... 

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