Zinc sulfide thermal properties

Zinc sulfide (Cleartran) 50,000-770 2.2 Reacts with strong oxidizing agents relatively inert with typical aqueous, normal acids and bases and organic solvents good thermal and mechanical shock properties low refractive index causes spectral distortions at 45° C... 

Choice of Material for the Window. The material used for the window has to meet certain criteria. First, the wavelength range over which the transmission is satisfactory is important. The stability of the material in contact with the solution is also of importance (particularly for aqueous acid or alkaline electrolyte solutions). However, other parameters such as the refractive index, the hardness, the thermal expansion coefficient, the standard form in which the material is available, and even the price also influence its choice. Practically, for aqueous solutions, the selection is restricted to a few materials, including silicon, calcium fluoride, zinc sulfide, and zinc selenide. The main properties of these materials, together with those of KRS-5, KRS-6, and CdTe, are gathered in Table VI. Various examples of transmission curves are given also in Figure 21. 

The key property required of the inorganic species is ability to build up (polymerize) around the template molecules into a stable framework. As is already evident in this article, the most commonly used inorganic species are silicate ions, which yield a silica framework. The silica can be doped with a wide variety of other elements (heteroatoms), which are able to occupy positions within the framework. For example, addition of an aluminium source to the synthesis gel provides aluminosilicate ions and ultimately an aluminosilicate mesoporous molecular sieve. Other nonsilica metal oxides can also be used to construct stable mesoporous materials. These include alumina, zirconia, and titania. Metal oxide mesophases, of varying stability, have also been obtained from metals such as antimony (Sb), iron (Fe), zinc (Zn), lead (Pb), tungsten (W), molybdenum (M), niobium (Nb), tantalum (Ta), and manganese (Mn). The thermal stability, after template removal, and structural ordering of these mesostructured metal oxides, is far lower, however, than that of mesoporous silica. Other compositions that are possible include mesostructured metal sulfides (though these are unstable to template removal) and mesoporous metals (e.g., platinum, Pt). 

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