Layers separators

With this testing method an evaluation is possible within shortest time, i.e. directly after the heat impulse. The high temperature difference between a delamination and sound material is affected - among other parameters - by the thickness of the layer. Other parameters are size and stage of the delamination Generally, a high surface temperature refers to a small wall thickness and/or layer separation [4],... 

Examples of solid - liquid systems with two liquid layers are given below the temperature is the temperature at which the two layers separate or the quadruple point. 

Dibromobutane from 1 4 butanediol). In a 500 ml. threenecked flask fltted with a stirrer, reflux condenser and dropping funnel, place 154 g. (105 ml.) of 48 per cent, hydrobromic acid. Cool the flask in an ice bath. Add slowly, with stirring, 130 g. (71 ml.) of concentrated sulphuric acid. To the resulting ice-cold solution add 30 g. of redistilled 1 4-butanediol dropwise. Leave the reaction mixture to stand for 24 hours heat for 3 hours on a steam bath. The reaction mixture separates into two layers. Separate the lower layer, wash it successively with water, 10 per cent, sodium carbonate solution and water, and then dry with anhydrous magnesium sulphate. Distil and collect the 1 4-dibromo-butane at 83-84°/12 mm. The yield is 55 g. 

Place 50 g. of anhydrous calcium chloride and 260 g. (323 ml.) of rectified spirit (95 per cent, ethyl alcohol) in a 1-litre narrow neck bottle, and cool the mixture to 8° or below by immersion in ice water. Introduce slowly 125 g. (155 ml.) of freshly distilled acetaldehyde, b.p. 20-22° (Section 111,65) down the sides of the bottle so that it forms a layer on the alcoholic solution. Close the bottle with a tightly fitting cork and shake vigorously for 3-4 minutes a considerable rise in temperature occurs so that the stopper must be held well down to prevent the volatilisation of the acetaldehyde. Allow the stoppered bottle to stand for 24-30 hours with intermittent shaking. (After 1-2 hours the mixture separates into two layers.) Separate the upper layer ca. 320 g.) and wash it three times with 80 ml. portions of water. Dry for several hours over 6 g. of anhydrous potassium carbonate and fractionate with an efficient column (compare Section 11,17). Collect the fraction, b.p. 101-104°, as pure acetal. The yield is 200 g. 

The experimental procedure to be followed depends upon the products of hydrolysis. If the alcohol and aldehyde are both soluble in water, the reaction product is divided into two parts. One portion is used for the characterisation of the aldehyde by the preparation of a suitable derivative e.g., the 2 4-dinitrophenylhydrazone, semicarbazone or di-medone compound—see Sections 111,70 and 111,74). The other portion is employed for the preparation of a 3 5-dinitrobenzoate, etc. (see Section 111,27) it is advisable first to concentrate the alcohol by dis tillation or to attempt to salt out the alcohol by the addition of solid potassium carbonate. If one of the hydrolysis products is insoluble in the reaction mixture, it is separated and characterised. If both the aldehyde and the alcohol are insoluble, they are removed from the aqueous layer separation is generally most simply effected with sodium bisulphite solution (compare Section Ill,74),but fractional distillation may sometimes be employed. 

Pure dialkylanilines may be prepared by refluxing the monoalkylaniline (1 mol) with an alkyl bromide (2 mols) for 20-30 hours the solid product is treated with excess of sodium hydroxide solution, the organic layer separated, dried and distilled. The excess of alkyl bromide paases over first, followed by the dialkylaniline. Di-n-propylaniline, b.p. 242-243°, and di-n-butylaniline b.p. 269-270°, are thus readily prepared. 

If you netralize the formic acid mix with 25% NaOH the layers separate out nicely. It takes 75 / of 25% NaOH to neutralize the soln for 150grm 88% formic, so you ll need a big sepatory funnel. After you hit ph 4.5 add it rery carefully cause it ll run away to 9+ real quick. You can then back extract the water with DCM, or I guess preferably ether. If you use too much DCM when extracting it sinks to the bottom and some product floats on the top, so you end up with three layers... But then my lab tech SUXSI (not that I d partake in iilegal activities. p"... 

Initial Run. - Into each of seven stoppered bottles was placed a mixture of ethyl sulphate [Et0-S02-0Et] (120 g.) and sodium nitrite [NaNOJ solution (120 g. in 160 c.c. of water.) The bottles were shaken mechanically for 20 hours, the pressure being released at intervals. The contents were then poured into a separating funnel, and the upper layer separated, dried over calcium chloride and distilled at 14mm., the distillate up to 60° being col-... 

A solution of 6-bromoindole (O.lOmol) in toluene (200 ml) was treated with Pd(PPh3)4 (5mol%) and stirred for 30 min. A solution of 4-fluorophenyl-boronic acid (0.25 M, 0.15 mol) in abs. EtOH was added, followed immediately by sal aq. NaHCOj (10 eq.). The biphasic mixture was refluxed for several hours and then cooled to room temperature. The reaction mixture was poured into sat. aq. NaCl (200 ml) and the layers separated. The aq. layer was extracted with additional EtOAc (200 ml) and the combined organic layers dried (Na2S04), filtered and concentrated in vacuo. The solution was filtered through silica gel using hexane-CHjCl -hexanc for elution and evaporated. Final purification by recrystallization gave the product (19 g, 90%). 

Mica splittings are processed from lower quaUty blocks and from sheets too thin for blocks and unsatisfactory for producing film. The splittings are packed for sale in three ways book form, which are laminae spHt to the desired thickness from the same book of mica, then dusted with mica dust, and restacked in book form pan packed, in which splitting layers are placed evenly in a pan, and each layer separated by a thin sheet of paper then pressed together and loose packed, in which splittings are si2ed with screens then padded loosely in a wooden box for shipment. 

Lubrication Additive. Cerium fluoride, CeF, can be used as an additive to lubricant formulations to improve extreme pressure and antiwear behavior (43). The white soHd has a crystal stmcture that can be pictured as [CeF] layers separated by [F] atom sheets, a layer stmcture analogous to that of M0S2, a material that CeF resembles in properties. 

Membrane Pervaporation Since 1987, membrane pei vapora-tion has become widely accepted in the CPI as an effective means of separation and recovery of liquid-phase process streams. It is most commonly used to dehydrate hquid hydrocarbons to yield a high-purity ethanol, isopropanol, and ethylene glycol product. The method basically consists of a selec tively-permeable membrane layer separating a liquid feed stream and a gas phase permeate stream as shown in Fig. 25-19. The permeation rate and selectivity is governed bv the physicochemical composition of the membrane. Pei vaporation differs From reverse osmosis systems in that the permeate rate is not a function of osmotic pressure, since the permeate is maintained at saturation pressure (Ref. 24). 

The stirring should be continued and the ice bath replaced by a hot-water bath, and the mixture refluxed gently for two hours. The flask is again cooled and 30 cc. of concentrated hydrochloric acid in 350 cc. of water is added through the separatory funnel. This should be added slowly as long as heat is evolved. The contents of the flask are then transferred to a separatory funnel, the ether layer separated and dried over calcium chloride. 

The reaction mixture is then transferred to a 2-I. round-bottom flask with wide neck, and to this is added all at once 300 g. of cracked ice, and the mixture is rapidly agitated by a rotary motion until the decomposition is complete (Note 7). Sufficient 30 per cent sulfuric acid is added to dissolve the magnesium hydroxide, and the mixture is then steam-distilled until oil no longer collects on the surface of the distillate. The distillate, which amounts to 1500-2500 cc., is saturated with sodium chloride and the upper layer separated. The aqueous layer is extracted with two loo-cc. portions of ether and the ether extract added to the alcohol layer. The ether solution is dried over anhydrous potassium carbonate, filtered, and heated carefully on the steam cone until all the ether is distilled. The crude alcohol is warmed one-half hour with about 5 g. of freshly dehydrated lime (Note 8). After filtering again and washing the lime with a little ether, the ether is distilled and the alcohol is distilled in vacuo from a Claisen flask (Note g). The carbinol distils at 88-93 /18 mm. (practically all distilling at 91°). The yield is 70-74 g. (61-65 P r cent of the theoretical amount) (Note 10). 

Fluorophenyl isothiocyanate [1544-68-91 M 153.2, m 24-26 , 26-27 , b 66 /2mm, 215 /atm, 228 /760mm, n 1.6116. Likely impurity is the symmetrical thiourea. Dissolve the isothiocyanate in dry CHCI3, filter and distil the residue in a vacuum. It can also be steam distd, the oily layer separated, dried over CaCl2 and distilled in vacuo. Bis-(4-fluorophenyl)thiourea has m 145 (from aq EtOH). [Browne and Dyson J Chem Soc 3285 1931 Buu Hoi et al. J Chem Soc 1573 1955 Olander Org Synth Coll Vol I 448 1941 ]. 

This material has been known for many years, being used originally in the making of electric lamp filaments. In principle vulcanised fibre is produced by the action of zinc chloride on absorbent paper. The zinc chloride causes the cellulosic fibres to swell and be covered with a gelatinous layer. Separate layers of paper may be plied together and the zinc chloride subsequently removed to leave a regenerated cellulose laminate. 

A multilayer-type structure probably due to cords in the molten zone between single arc sprayed (0.25 MPa) Ni droplets and steel substrate were found in AES point depth profiles [2.158]. That particular arc spraying condition turned out to yield the best adhesion. Plasma-sprayed AI2O3 layers separated from pre-oxidized Ni Substrate had a micrometer-thick NiO layer on the substrate-sided face and micrometer-deep oxide interdiffusion [2.159]. In this work also, AES point depth profiling substantiated technological assumptions about adhesion mechanisms. 

Acetylene and Potassium in Liquid Ammonia Potassium (40 g) is dissolved in 1 liter of dry liquid ammonia. Dry acetylene is then bubbled into the solution until the blue color is discharged. A solution of 15 g of estrone in 300 ml of dioxane is prepared and diluted with 300 ml of ether, cooled, and added to the potassium acetylide solution over a period of 10 min. The liquid ammonia is allowed to evaporate, an additional 500 ml of ether is added, and the mixture is allowed to stand overnight. About 3 liters of 5 % sulfuric acid is added and the organic layer separated. The water layer is re-extracted with fresh ether, and the combined ether extracts are washed twice with 5 % sodium carbonate solution, th6n several times with water, and finally evaporated under reduced pressure. The residue is dissolved in 150 ml of methanol, then an equal quantity of hot water is added and the mixture cooled. The precipitated solid is collected, washed with cold 60 % methanol and crystallized once from methanol-water to give 14.8 g (85%) of 17a-ethynylestradiol mp 143-144°. 

The residue (12 g) which contains the 18-iodo-18,20-ether is dissolved in 200 ml of acetone, 5 g of silver chromate is added Note 3) and after cooling to 0°, 11.8 ml of a solution of 13.3 g of chromium trioxide and 11.5 ml of concentrated sulfuric acid, diluted to 50 ml with water is added during a period of 5 min. After an additional 60 min, a solution of 112 g of sodium acetate in 200 ml of water is added and the mixture diluted with benzene (400 ml), filtered and the benzene layer separated. The aqueous phase is reextracted with benzene, washed with half-saturated sodium chloride solution, dried and evaporated to yield 11.2 g of a crystalline residue. Recrystallization from ether gives 7.2 g (72%) of pure 3/5, 1 la, 20/5-trihydroxy-5a-pregnan-18-oic acid 18,20 lactone 3,11-diacetate mp 216-218°. 

Preparation of l9-Norandrost-A-ene-3, l-dionef A solution of 1.1 g of 10y5-cyano-19-norandrost-5-ene-3,17-dione bis-ethylene ketal in a mixture of 15 ml of ethanol and 15 ml of toluene is carefully added to a vigorously stirred suspension of 10 g of sodium in 150 ml of boiling toluene. The addition is regulated to maintain the reaction mixture at the boiling point of the solvent. Another 40 ml of anhydrous ethanol is then added at the same rate. The solution is cooled and the excess of sodium is decomposed by addition of 95% ethanol. The reaction mixture is then diluted with water, the toluene layer separated and the aqueous phase extracted twice with ether. The organic solution is washed with water, dried and evaporated to yield 1 g of an amorphous mixture of the bis-ethylene ketals of 19- norahd-rost-5- and -5(10)-ene-3,17-dione (Note 1). 

The failure criterion must be applied to determine the maximum values of Nx and AT that can be sustained without failure of any layer. Actually, the failure criterion is applied to each layer separately. For the special orientation of cross-ply laminates, the Tsai-Hill failure criterion for each layer can be expressed as... 

The model just presented describes what electrochemists call the diffuse part of the double layer and no account is made of the inner layer effects such as the plane of the closest approach. To have an idea what the impact of the effects predicted by this model on the measured capacitance could be, we assume the traditional inner and diffuse layer separation. However, we... 

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