Energy and Chemical Reactions

Low energy chemical reactions and quenching of excited metal atoms has been investigated in crossed-beams. Examples are the studies of the sodium-nightglow precursor reaction ... 

The explanation for these phenomena was similar to that of Xu et al. [44]. According to sonochemistry, ultrasound can cause high-energy chemical reactions and increase the reactivity of particles. Therefore, lead zirconate tita-nate (PZT) phase can be formed at lower calcination temperature (400 °C) in the created gels. This advantage, together with low-cost starting materials used, will make the hybrid method an attractive approach for industrial febrication of PZT ceramics. It is also believed to be applicable to other materials similar to PZT. 

Polymeric materials also experience deterioration by means of environmental interactions. However, an nndesirable interaction is specified as degradation rather than corrosion because the processes are basically dissimilar. Whereas most metallic corrosion reactions are electrochemical, polymeric degradation is physiochemical that is, it involves physical as well as chemical phenomena. Furthermore, a wide variety of reactions and adverse consequences are possible for polymer degradation. Polymers may deteriorate by sweUing and dissolution. Covalent bond rupture as a result of heat energy, chemical reactions, and radiation is also possible, typically with an attendant reduction in mechanical integrity. Because of the chemical complexity of polymers, their degradation mechanisms are not well understood. 

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