Potassium metal alloys

The most commonly used Hquid metal is sodium—potassium eutectic. Sodium, potassium, bismuth, lithium, and other sodium—potassium alloys also are used. Mercury, lead, and lead—bismuth eutectic have also been used however, these are all highly toxic and appHcation has thus been restricted. 

These reactions are usehil for the preparation of homogeneous difunctional initiators from a-methylstyrene in polar solvents such as tetrahydrofuran. Because of the low ceiling temperature of a-methylstyrene (T = 61° C) (26), dimers or tetramers can be formed depending on the alkaU metal system, temperature, and concentration. Thus the reduction of a-methylstyrene by sodium potassium alloy produces the dimeric dianionic initiators in THF (27), while the reduction with sodium metal forms the tetrameric dianions as the main products (28). The stmctures of the dimer and tetramer correspond to initial tail-to-tail addition to form the most stable dianion as shown in equations 6 and 7 (28). 

Sodium—potassium alloy is easily prepared by melting the clean metals ia an iaert atmosphere or under an iaert hydrocarbon, or by the reaction of sodium with molten KCl, KOH, or soHd K CO powder. 

Preparation of Acyloins. When aUphatic esters are allowed to react with metallic sodium, potassium, or sodium—potassium alloy in inert solvents, acyloins (a-hydroxyketones) are formed (45) ... 

Caution Disposal of residues must he made with care. When excess metal, especially sodium-potassium alloy, is used, the residues can be pyrophoric ... 

Kohlenstoff-hydrat, n. carbohydrate, -kalium, n. potassium carbide, -kem, m. carbon nucleus. -kette,/. carbon chain, -legiening,/, carbon alloy, -metall, n. carbide, kohlenstoffrelch, a. rich in carbon. Kohlenstoff-silicium, n. carbon silicide. -ske-lett, n. carbon skeleton, -stahl, m. carbon steel, -stein, m. carbon brick, -sticlKtoff-titan, n. titanium carbonitride. -sulfid, n. 

Bonilla, C. F., D. L. Sawhuey, and N. M. Makansi, 1962, Vapor Pressure of Alkali Metals III, Rubidium, Cesium, and Sodium-Potassium alloy up to 100 psia, Proc. 1962 High Temperature Liquid MetaI Heat Transfer Tech. Meeting, BNL-756, Brookhaven, NY. (3)... 

Potassium-sodium alloy See Potassium-sodium alloy Metal oxides... 

Potassium Non-metal oxides Potassium-sodium alloy Carbon dioxide Sodium Non-metal oxides Titanium Carbon dioxide Uranium Carbon dioxide... 

Reductive dehalogenation cannot be completely controlled, and mostly complicated mixtures were formed which are difficult to separate. Salt elimination opens the possibility of a reaction aimed at polysilane formation. Some examples are shown in Fig. 2. The key compounds are the alkali metal cyclosilanes, which we have isolated via the mercury compounds by the action of sodium/potassium alloy and used for the first time [13]. 

Nuclear and magneto-hydrodynamic electric power generation systems have been produced on a scale which could lead to industrial production, but to-date technical problems, mainly connected with corrosion of the containing materials, has hampered full-scale development. In the case of nuclear power, the proposed fast reactor, which uses fast neutron fission in a small nuclear fuel element, by comparison with fuel rods in thermal neutron reactors, requires a more rapid heat removal than is possible by water cooling, and a liquid sodium-potassium alloy has been used in the development of a near-industrial generator. The fuel container is a vanadium sheath with a niobium outer cladding, since this has a low fast neutron capture cross-section and a low rate of corrosion by the liquid metal coolant. The liquid metal coolant is transported from the fuel to the turbine generating the electric power in stainless steel... 

Caution. The residues on the glassware and the frit may contain sodium-potassium alloy and/or tris(trimethylsilyl)arsine and should not be exposed to air until disposal. tert-Butyl alcohol and isopropyl alcohol can be used to destroy these pyrophoric compounds however, this should be performed in a fume hood, as arsine gas may be generated. The solid on the frit can be mixed with class D metal fire extinguisher and subsequently treated with either of the aforementioned alcohols. 

The sodium-potassium alloy (45-90 weight %K) is molten at room temperature and cesium melts at 28.5°, so both of these are easily handled as liquids. For example, a hypodermic syringe is convenient for their transfer. The sodium-potassium alloy is made by heating the two metals together while they are protected by a high-molecular-weight hydrocarbon. 

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