Evaporation solids

NOTE When a boiler first starts up from cold, there is always some initial condensation arising from combustion (which generally falls to the rear of the boiler and may form a pool of water). This quickly evaporates and should not be confused with tube leaks that leave evaporated solids behind. 

Reaction of ammonium hexanitrocerate and cyclopentadienylsodium under inert conditions gives tris(cyclopentadienyl)cerium and sodium nitrate, removed by filtration before evaporation of solvent [1]. When the filtration step was omitted, and the evaporated solid mixture was heated to 75°C, a violent explosion occurred. This may have involved complexes of the type Ce(N03)Cp2.NaN03[2], but a direct redox reaction between the reactive CeCp3and the oxidant is also possible. 

Atomic structures of field evaporated solid surfaces... 

In the second, really a series of experiments, ammonium bicarbonate was added to an excess of neat isopropylamine. Evidence for reaction included the formation of bubbles in the amine and the smell of ammonia. Several such mixtures were allowed to stand with variable amounts of stirring until the excess amine had evaporated. Solid powders remained. IR spectra of fluorolube mulls of the powders were neither identical nor were they simple additions of the spectra... 

To a suspension of 500 mg (1.74 mmoles) of the (S)-6-(2-oxo-l,3-oxazolidin-4-ylmethyl)-4,9-dihydro-3-pyrano-[3,4-b]indol-l-one in 10 ml of methanol were added 0.12 ml (1.9 mmoles) of methanesulfonic acid. The mixture was left under stirring at the reflux temperature for 3 hours. The solvent was evaporated to dryness under reduced pressure, the residue dissolved with 10 ml of a saturated bicarbonate solution and extracted three times with dichloromethane. The combined organic phases were dried and evaporated to dryness and the evaporated solid recrystallised from ethanol to give 517 mg (93%) of the title ester as a yellow crystalline solid. Melting point 178°-180°C. 

To a stirred suspension of 4.6 g (13.8 mmoles) of the (S)-3-(2-hydroxyethyl)-5-(2-oxo-l,3-oxazolidin-4- ylmethyl)-lH-indol-2-carboxylic acid ethyl ester in 42 ml of dichloromethane were added 4.2 ml of pyridine, 3.9 g (20.7 mmoles) oftosyl chloride and 170 mg (1.38 mmoles) of dimethylaminopyridine and the stirring continued at room temperature for 20 hours. The reaction mixture was poured over 20 ml of 3 N, HCI precooled to 0°C and extracted twice with dichlormethane. The organic phases were washed with brine, dried on anhydrous sodium sulphate and the solvent evaporated to dryness. The evaporated solid was crystallised with isopropyl alcohol to give 6.4 g (95%) of the title compound as a white crystalline solid. Melting point 166.4°-168.2°C. 

Cellulose acetate has replaced cellulose nitrate in many products, for example, in safety-type photographic films. When a solution of cellulose acetate in acetone is passed through the fine holes of a spinneret and the solvent evaporates, solid filaments are produced. Acetate rayon is prepared from threads of these filaments. Some applications and solvents of commercial cellulose acetate grades are summarized in Table 9-5. 

B °C is the convenient temperature of a bath of acetone containing pellets or slowly evaporating solid C02. 

In the following equilibrium systems for a pure substance (not a solution) solid liquid (s l) fusion liquid vapour (/ g) evaporation solid vapour (s g) sublimation... 

Formation of polymer ligand Evaporation Solid polymer ligand chelate (Fe(II)porphyrin Fe(II)porphyrin complex of solvent > 10 4 mole per unit gramm of polymer matrix)... 

Extract with DCM. Dried with anhydrous sodium sulfate and concentrated in a rotary evaporator Solid-phase extraction onto a mini activated carbon column, elute with acetone. 

In thermal evaporation, solid materials are first vaporized by heating at sufficiently high temperature in vacuum, and then a thin film is formed on a cooler substrate by condensation of the vapor. This technique can be used for the deposition of thin layers made of such metals as Ag or Pt that are active in gas separation. 

When the water is evaporated, solid hydrated magnesium chloride is left. After drying, it is melted (at 708°C) and then electrolyzed in a huge steel pot that serves as the cathode. Graphite bars serve as the anodes. The electrode reactions are... 

Screw, jacketed, atmos. (conduction) 2-30 rpm area 4-60 m volume 0.1-3 m. 0.03-0.5 kg water evaporated/s. Heat transfer coefficient 4-60 W/m °C with 4-10 for hollow screw and 5-35 for hollow paddles power 140 MJ/Mg. Continuous band, vacuum, (conduction) 2.2 kg steam/kg water evaporated solid capacity 2-5 g dry solids/s m belt area belt size < 8 m. ... 

Prompt refrigerated storage (1% aqueous solutions of the acids are stable for several weeks. Freezer storage as evaporated solids is recommended for longer periods). 

Evaporation from an external or internal oven. Different kinds of ovens and mini-ovens have been developed to evaporate solids with melting points up to 2,000°C (Lang et al. 2000 Barue et al. 2002 Kidera et al. 2002 Zavodszky et al. 2002). The ovens are usually very close to (or sometimes inside) the plasma chamber. An important requirement is the precise online monitoring of the oven temperature. Because evaporation is a continuous process, ovens are usually used in continuously operating ion sources. 

Evaporating solid polymeric particles (accompanied by considerable pyrolysis) and codepositing the volatile products (mostly radicals) with the metal vapor are used less often. This technique is employed for the formation of 10-mn-diameter copper islets in a polyethylene matrix. The explosive evaporation of a metal wire coated with a polymer and pulsed mechanochemical interactions (of the Bridgeman anvil type), etc. are the modifications of this method. Recently, interest has been shown in the ionic spraying of metals onto polymeric surfaces. Studies of the vacuum deposition of Au and Zn on PE and PTFE should be noted. " ... 

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