Evaporation of water

Emulsion polymerization also has the advantages of good heat transfer and low viscosity, which follow from the presence of the aqueous phase. The resulting aqueous dispersion of polymer is called a latex. The polymer can be subsequently separated from the aqueous portion of the latex or the latter can be used directly in eventual appUcations. For example, in coatings applications-such as paints, paper coatings, floor pohshes-soft polymer particles coalesce into a continuous film with the evaporation of water after the latex has been applied to the substrate. 

In oaken battels, slow evaporation of water and alcohol through the staves is ordinarily compensated for by refilling and topping each battel by... 

The printing of newspapers is conducted at very high speeds, often reaching 3000 feet per miaute. AH three printing processes utilize similar quaHty newsptint which, essentiaHy, is made of groundwood or thermomechanical pulp. Presses are fed a continuous web of newsptint that unwiads from a feed roUer. Inks dry by absorption of Hquid iato the porosity of the substrate. Some evaporation of water ia a flexo pubHcation ink can accelerate the dryiag process. 

Tetrapotassium peroxodiphosphate is produced by electrolysis of a solution containing dipotassium phosphate and potassium fluoride (52). Alkalinity favors the formation of the P20 g anion, whereas the PO anion is produced in larger yields in acidic solution. It is therefore possible to obtain an 80% yield of K4P20g by choosing the proper conditions. The tetrapotassium peroxodiphosphate can be crysta11i2ed from solution by evaporation of water to form a slurry. The crystals can be separated from the slurry and dried. The material is noncorrosive and cannot be catalyticaHy decomposed by iron ions. 

Condensed Phosphoric Acid. The largest use of polyphosphoric (superphosphoric) acid is as an intermediate in the production of high quahty Hquid fertilizers. The TVA pioneered the development of electric-furnace superphosphoric acid for this appHcation. However, wet-process superphosphoric acid prepared by evaporation of water from wet-process phosphoric acid has almost completely replaced furnace-grade acid in fertilizer manufacture. 

Commercial grades of sodium aluminate are obtained by digestion of aluminum tnhydroxide in aqueous caustic at atmospheric pressure and near the boiling temperature (7). Digestion of the aluminum hydroxy oxide in aqueous sodium hycboxide [1310-73-2] requbes pressures of up to 1.38 MPa (13.6 atm) and temperatures of about 200°C. Dry sodium aluminate is obtained by evaporation of water. Several processes for the production of sodium aluminate are known that do not reqube the addition of water. In one process, bauxite reacts with molten sodium hycboxide at approximately 400°C (8) in... 

Isolation of dry, normal ammonium acetate, prepared by neutralizing acetic acid with anhydrous ammonia or ammonium carbonate, is difficult because of ammonia loss during evaporation of water. Consequendy, commercial grades of ammonium acetate are often mixtures of the neutral and acid salts, or are suppHed as ammonium acetate solution [8013-61-4]. 

Vacuum flash processes, which operate under the atmospheric boiling point of the solution, include the Uhde—LG. Farbenindustrie process and the closely related Kestner process (22). In these, ammonia, nitric acid, and recirculated ammonium nitrate solution are fed into the neutralizer. Hot solution overflows to an intermediate tank and then to a flash evaporator kept at 18—20 kPa (0.18—0.2 atm) absolute pressure. Partial evaporation of water at this point cools and concentrates the solution, part of which is routed to evaporation. The rest is circulated to the neutralizer. 

The manufacture of sugar was early understood to be an energy-intensive process. Cuba was essentially deforested to obtain the wood that fueled the evaporation of water from the cane juice. When the forests were gone, the bagasse burner was developed to use the dry cane pulp, called bagasse, for fuel. Bagasse was no longer a waste product its minimal value is the cost of its replacement as fuel. 

Morta.r, Mortar, principally slaked lime and sand, sets because of the evaporation of water, the deposition of calcium hydroxide, and the absorption of water by the bricks or cement blocks, foUowed by hardening as a result of the absorption and reaction of carbon dioxide. 

FIG. 17-56 Effect of drop diameter on time for complete evaporation of water drops. 

Aluminum sleeves used in an annealing machine to heat treat copper rod failed rapidly (Figs. 8.12 and 8.13). Attack was caused by a caustic that concentrated due to evaporation of water in the annealing sleeve. 

Figure 13.8 A brass tube showing plug-type dezincification. The white patch above the plug on the external surface was caused by dissolved solids, concentrated by evaporation of water leaking through the porous dezincified plug.

The increase of restrictive regulations on the use of organic solvents favoured the increasing use of latex-based adhesives. Because of the slow evaporation of water, these adhesives show less tack and can suffer bacterial attack. Infrared heaters and ovens can be used to favour the evaporation of water. Often a small amount of solvent (coalescing aid) is added to the latex system to improve wetting and coalescence of the latex particles. 

R-(-)-Phenylglycinol (5 g, 36.5 mmol) was added to a solution of Zincke salt 115 (10.3 g, 33.3 mmol) in n-butanol (100 mL) at 20 °C. The resulting deep red solution was refluxed during 20 h. Removal of the solvent under reduced pressure left a residue that was treated with HpO (70 mL). The precipitate (2,4-dinitroaniline hydrochloride) was eliminated by filtration, and the operation was repeated twice. The combined aqueous phase was basified with concentrated ammonia (5 mL) and washed twice with EtOAc (200 mL) in order to remove the remaining 2,4-dinitroaniline and the excess of R- )-phenylglycinol. Evaporation of water gave salt 122 (7.53 g, 86%) as a pale orange gum. 

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