Oxide glasses amorphous solids

Diffusion coefficients in amorphous solids such as oxide glasses and glasslike amorphous metals can be measured using any of the methods applicable to crystals. In this way it is possible to obtain the diffusion coefficients of, say, alkah and alkaline earth metals in silicate glasses or the diffusion of metal impurities in amorphous alloys. Unlike diffusion in crystals, diffusion coefficients in amorphous solids tend to alter over time, due to relaxation of the amorphous state at the temperature of the diffusion experiment. 

Solubility and speciation. Minimum requirements for reliable thermodynamic solubility studies include (i) solution equilibrium conditions (ii) effective and complete phase separation (iii) well-defined solid phases and (iv) knowledge of the speciation/oxidation state of the soluble species at equilibrium. Ideally, radionuclide solubilities should be measured in both oversaturation experiments, in which radionuclides are added to a solution untU a solid precipitates, and undersaturation experiments, in which a radionuchde solid is dissolved in aqueous media. Due to the difference in solubilities of crystalline versus amorphous solids and different kinetics of dissolution, precipitation, and recrystalhzation, the results of these two types of experiments rarely agree. In some experiments, the maximum concentrahon of the radionuchde source term in specific water is of interest, so the sohd that is used may be SF or nuclear waste glass rather than a pure radionuclide solid phase. 

Even before alchemy became a subject of study, many chemical reactions were used and the products applied to daily life. For example, the first metals used were probably gold and copper, which can be found in the metallic state. Copper can also be readily formed by the reduction of malachite—basic copper carbonate, Cu2(C03)(0H)2—in charcoal fires. Silver, tin, antimony, and lead were also known as early as 3000 BC. Iron appeared in classical Greece and in other areas around the Mediterranean Sea by 1500 BC. At about the same time, colored glasses and ceramic glazes, largely composed of silicon dioxide (Si02, the major component of sand) and other metallic oxides, which had been melted and allowed to cool to amorphous solids, were introduced. 

The reaction between metalated PPO and ethylene oxide under different reaction conditions was studied by Pedretti et al. and Farias et al.. The thus modified PPO was amorphous solid product having a glass transition temperature in the range of 170 - 220° C. The polymer was soluble in polar solvents. 

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