Mixed cobalt nitrate-acetate

Also not new are the phenomena seen in nanostructures—all sol-gel (e.g.. Chapter 13 all aerogels are nanocrystalline ) and life chemistry is nanostruc-tural, and chemists long have been able to prepare molecular clusters and nanocrystalline powers by vaporization or, better, by decomposition of precursors (typically hydroxides, carbonates, nitrates, acetates, citrates, and so on). Even the recent production of biphasic or polyphasic nanostructures from polymers had been preceded by the decomposition of mixed crystals [e.g., CaMg(Co3)2, dolomite, to CaO and MgO]. Carbon and SiC fibers (Nicalon ) are nanostructural. In this book, nanocrystalline cobalt from 1966 is mentioned (Chapter 18). Naturally, the nanostructural works of chemists could not be directly examined before the advent of electron microscopes, but more indirect... 

Ammonium tetrathiocyanatomercurate(II)-cobalt sulphate test This test is similar to that described under reaction 8, except that a minute amount of a dilute solution of a cobalt salt (nitrate, sulphate or acetate) is added. Coprecipitation of the cobalt tetrathiocyanatomercurate(II) yields a blue precipitate composed of mixed crystals of Zn[Hg(SCN)4] + Co[Hg(SCN)4], Iron(II) salts give a red colouration but this can be eliminated by the addition of a little alkali fluoride (colourless [FeF6]3- ions are formed). Copper salts should be absent. 

Potassium or sodium-potassium alloy mixed with ammonium nitrate and ammonium sulfate results in explosion (NFPA 1986). Violent reactions may occur when a metal such as aluminum, magnesium, copper, cadmium, zinc, cobalt, nickel, lead, chromium, bismuth, or antimony in powdered form is mixed with fused ammonium nitrate. An explosion may occur when the mixture above is subjected to shock. A mixture with white phosphorus or sulfur explodes by percussion or shock. It explodes when heated with carbon. Mixture with concentrated acetic acid ignites on warming. Many metal salts, especially the chromates, dichromates, and chlorides, can lower the decomposition temperature of ammonium nitrate. For example, presence of 0.1% CaCb, NH4CI, AICI3, or FeCb can cause explosive decomposition at 175°C (347°F). Also, the presence of acid can further catalyze the decomposition of ammonium nitrate in presence of metal sulfides. 

The starting materials were soluble salts, cobalt acetate (Co(C2H302)2 H2O) and iron nitrate (Fe(N03)2 9H2O). These salts produce hydroxides (M(OH)2), oxyhydroxides (MOOH) or hydrated oxides in water, where M is Co or Fe. These solutions were reacted with lithium hydroxide. Diluted ammonium hydroxide (3M) was added to form stable colloids (Barboux, 1991). Lithium hydroxide and cobalt acetate were dissolved separately in distilled water. These two solutions were then mixed together and stirred vigorously. The hydrolysis of the mixture was promoted by slow addition of 3M ammonium hydroxide. Similarly, sols with ferric nitrate, or ferric nitrate plus cobalt acetate, were prepared. The sols used for coating were diluted to give a 2 1 ratio of moles water to moles oxide. 

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