Inorganic nonoxides

Microporous inorganic materials dominated historically by the 2eohtes and alumosilicates, and the great variety of more recent nonoxide and coordination framework materials should also be mentioned here (171—174) but not discussed in detail. This type of molecular recognition is usually known as molecular sieving. 

Various inorganic semiconductors (p-type and/or n-type nonoxide semiconducting materials) sucb as amorphous or crystalline silicon (a-Si or c-Si), gallium arsenide (GaAs), cadmium telluride (CdTe), gallium phosphide (GaP), indium phosphide (InP), copper... 

Table 28-5 lists acids commonly used for dissolving inorganic materials. The nonoxidizing acids HC1, HBr, HF, H3P04, dilute H2S04, and dilute HC104 dissolve metals by the redox reaction... 

Many inorganic materials can be dissolved in strong acids with heating. Glass vessels are often useful, but Teflon, platinum, or silver are required for HF, which dissolves silicates. If a nonoxidizing... 

It is well known that anhydrous nonoxidizing inorganic acids such as hydrogen chloride and hydrogen bromide do not dissolve metals. These two compounds are stored in steel cylinders without any appreciable corrosion of the metal. The same was true of anhydrous hydrogen fluoride that was stored and delivered in steel cylinders for the past seven decades. 

This procedure may result in a concentration of cumene hydroperoxide of 9—12% in the first reactor, 15—20% in the second, 24—29% in the third, and 32—39% in the fourth. Yields of cumene hydroperoxide may be in the range of 90—95% (18). The total residence time in each reactor is likely to be in the range of 3—6 h. The product is then concentrated by evaporation to 75—85% cumene hydroperoxide. The hydroperoxide is cleaved under acid conditions with agitation in a vessel at 60—100°C. A large number of nonoxidizing inorganic acids are useful for this reaction, eg, sulfur dioxide (19). 

Charcoal is basically the solids that remain after nonoxidative pyrolysis of organic material for present purposes, the range of organic material is restricted to the cellular material of plants. Such solid residues are composed of graphite-like materials as the principal constituent, and such other inorganic compounds as are usually found between 40 and 0.02 percent of the total weight of the charcoal. The inorganic residues in the charcoal are usually expressed as so much metal oxide and... 

Natural rubber offers excellent resistance to most inorganic salt solutions, alkalies, and nonoxidizing acids. Hydrochloric acid will react with soft rubber to form rubber hydrochloride, and therefore, it is not recommended that natural rubber be used for items that will come into contact with that... 

The Inorganic reducing dissolved salts or by condensing metal vapors in an inert gas. Although this is an expensive process, very fine oxide and nonoxide particles are made on an industrial scale by gas-phase nucleation, e.g., silica, titania, and metal nitrides. Examples of all these techniques are described in Chapter 8. 

Dilute nonoxiding inorganic and organic acids. Resistance is improved if acids are deaerated. 

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