Technical water glass solution

Variations of Silica Sol Manufacturing Process. As shown in Figure 4, the four methods, A-l, A-2, B-l, and B-2, use different technical combinations of nucleation, particle growth, and concentration. In any of these methods the raw material aqueous water-glass solution is diluted, and sodium is removed with a cation-exchange resin to obtain an active silicic acid. The characteristics of these four processes are shown in Table I. 

Alkoxides are described in some literature as expensive educts prohibiting mass production. A solution to this problem is the use of cheaper raw materials such as water glass or sodium silicate (Na2 i03) for sihca [50], which is now used as general precursor for commercial aerogel synthesis for technical applications. A silica hydrogel is generated by acidification of the aqueous sodium silicate solution with e.g. HCl or H2SO4 [51,52]. 

Ethylene Dibromide. Technical material was washed three times with concentrated sulfuric acid, rinsed with water, and dried over calcium chloride. It was then distilled through 1 foot of glass beads. The fraction boiling between 130.2° and 131.2° C. was used. Every third day an aqueous solution was prepared by weighing approximately 0.5000 gram of ethylene dibromide into 2000.0 grams of water. It was stored in a dark bottle to minimize light decomposition. 

Soluble complexes are formed with metallic oxides, especially in the presence of alkali hydroxides. The strong tendency of hexitols to dissolve metallic oxides presents considerable technical difficulty in their manufacture and for this reason glass, rubber or stainless-steel equipment is used. In some instances well defined complexes can be isolated, particularly with alkaline earth oxides or mixtures with ferric oxide. These complexes absorb carbon dioxide and water and are unstable in dilute aqueous solution. Their structures are not established, but are inferred from analytical and physical measurements. Diehl has reviewed the subject. 

Weigh the calculated amount of potassium dichromate on a technical chemical balance and triturate it in a mortar. Pour the powdered salt into a chemical beaker, and add 50 ml of water. Place the beaker on an asbestos gauze and heat with the flame of a gas burner almost to boiling while mixing the solution with a glass rod. Why is the solution heated almost to boiling and only then filtered ... 

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