High Temperatures Methods

This route of synthesis consists of two main techniques [68]  

Arc Discharge An electrical discharge is produced between two graphite electrodes, which heats and vaporizes the electrodes, and after, being condensed in the form of a soot containing nanotubes. 

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High temperature acetylation of cellulose above 50°C produces cellulose acetate from low purity wood pulp cellulose in shorter reaction times. In a high temperature method recently disclosed (102), cellulose reacts with 200—400% acetic anhydride in the presence of <5% acid catalyst at 68—85°C for 3—20 min. After the acid catalyst is neutralized with magnesium acetate, the cellulose acetate is hydrolyzed at 120°C for two hours (103). Several modified catalyst systems have been developed for acetylation of cellulose above 90°C (89,90). 

Titanium (IV) iodide may be prepared by a variety of methods. High-temperature methods include reaction of titanium metal with iodine vapor,1-3 titanium carbide with iodine,4 titanium(IV) oxide with aluminum (III) iodide,5 and titanium (IV) chloride with a mixture of hydrogen and iodine. At lower temperatures, titanium (IV) iodide has been obtained by the combination of titanium and iodine in refluxing carbon tetrachloride7 and in hot benzene or carbon disulfide 8 a titanium-aluminum alloy may be used in place of titanium metal.9 It has been reported that iodine combines directly with titanium at room temperature if the metal is prepared by sodium reduction of titanium (IV) chloride and is heated to a high temperature before iodine is... 

Several high-temperature methods leading to fluoridated apatites can be found in the literature they involve solid-gas reaction, pyrolysis or crystal growth processes. 

The high-temperature method represents a convenient one-step synthesis of these complexes in moderate (millimolar) quantities. There have been recent reports of multistep syntheses of both Ni(C7H10)3 and Pd(C7H,c)3 by conventional reductive methods and their derivative chemistry has been extensively explored (35, 141). 

These two procedures readily lend themselves to the production of kilograms of tin (IV) chloride method 6) is somewhat preferable because it is relatively inconvenient to keep large amounts of tin in the molten condition, as required in the high-temperature method. 

Calcium Aluminates. CAS 065997-16-2], Four in number. Iiave been prepared by high-temperature methods and identified. 3CaO- AI>Oi. at l,535aC. decomposes with partial fusion 5CaO- ALOj. nip 1,455 C, CaO AbOt. tnp 1.590°C. 3CaO- AI Oi. mp 1.720 C. 

Calcium Aluminosilicates. Two in number, have been prepared by high-temperature methods and identified 2CaO AhOi SiCL. gehlinile CaO- AI Oi 2SiO . anorthite. 

Ceramic fibers used in composites are usually made by high-temperature methods. Carbon (graphite) fiber, for example, can be made by the thermal decomposition of fibers of polyacrylonitrile, a long-chain organic molecule also used to make the textile Orion ... 

Typical images of c-BN grown by the high-pressure high-temperature method are shown in Fig. 3. 

Fluorine, 1 136 as fluorinating agent, 4 137 by high-temperature method, 1 138... 

The entire spectrum of tools in synthetic inorganic chemistry, including high temperature methods, precipitation, solvothermal synthesis, sol-gel chemistry, chemical vapor deposition (CVD), and soft matter techniques adopted in part from organo-metallic chemistry, have been applied to synthesize the active mass of catalysts. Table 4.2.1 summarizes basic techniques. The preparation methods differ whether... 

Similar reactions of B-hydropyrazaboles with active hydrogen compounds such as pyrocatechol phenol thiols or additional pyrazole are equally facile but require high temperatures (method D). Therefore, the reaction of pyrazabole with o-phenylenediamine may proceed via the expected substituted pyrazabole as an intermediate. However, the latter is unstable under the reaction conditions and condenses further to yield the borazine derivative 10 with the elimination of pyrazole... 

The column temperature was also an important factor to successfully join IPC with atomic absorption spectrometry in the online speciation of Cr(HI) and Cr(VI) [37], Some concerns for high temperature methods include column stability [38] and potential on-column degradation of analytes [39]. 

Borate minerals are common but synthesized examples are relatively rare [11]. We also notice that the borate crystals were usually grown by high temperature methods, exemplified by the high temperature flux and melt techniques [12-14]. There were a few reports on the preparation of borates by using the sol-gel technique. 

The structure of BiSI is built up of (Bi2S2I2) double chains parallel to the c-axis.795 The compound Bii9S27Br3, obtained by high-temperature methods, and the analogous iodide are isostructural, but attempts to prepare the chloride were unsuccessful.796... 

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