Evaporators Ball mills

Fish tissue is homogenized with a Polytron apparatus using methanol as a solvent, or extracted in a ball mill with hexane. The extracts are evaporated to dryness, dissolved in ethyl acetate toluene, and cleaned up on a gel permeation column followed by an alumina column. Analysis is performed by GC/NPD (Muir et al. 1981). Recovery is acceptable (79-97%) and limit of detection is 10 ng/g (Muir et al. 1981). 

Solid-state catalytic hydrogenations in the absence of any solvent can be easily and quantitatively performed in ball-mills that allow for evaporation and filling with gases. For example, the Diels-Alder adduct of maleic anhydride and cyclopentadiene 2 hydrogenates readily upon milling with palladium on charcoal in an atmosphere of hydrogen in 200-g batches to give 99, which is easily sublimed off from the catalyst [22] (Scheme 10). 

Deters (14) vibromilled a blend of cellulose and cellulose triacetate. The acetic acid content of cellulose acetate decreased with grinding time (40 h) while that of the cellulose increased, suggesting the formation of a block or graft copolymer or of an esterification reaction by acetic acid developed by mechanical reaction. Baramboim (/5) dissolved separately in CO polystyrene, poly(methyl methacrylate), and poly(vinyl acetate). After mixing equal volumes of solutions of equivalent polymer concentration, the solvent was evaporated at 50° C under vacuum and the resultant product ball-milled. The examination of the ball-milled products showed the formation of free radicals which copolymerized. 

The aldehyde/ketone 1 (4.00 mmol), or the ketone 7 (2.00 mmol), or the isothio-cyanate 5 (2.00 mmol) was ball-milled with the solid hydrazine-hydroquinone complex 2 (2.00 mmol) at 25-30 °C for lh (3 h in the case of Id). The yield was quantitative in all cases, as spectroscopically pure mixtures of 3, 6, 8 with 4 were obtained. Hydroquinone 4 was removed by 5 min trituration with 20 mL of water, filtration and three washings with 2 mL of water, each. The residue was dried in a vacuum to obtain the pure products. 4 was recycled from the aqueous washings by evaporation, addition of 1.0 g of 80% hydrazine hydrate in water per 4 mmol of initially reacted 2 and recrystallization to give 520 mg (91%) of pure 2 after filtration, washing with water and drying. 

The thioureido-acetamide lb (2.00 mmol) and 2 (2.00 mmol) were weighed into a 10-mL ball-mill vessel. The mixture became immediately solid and was ball-milled at 25 Hz for 1 h. 3b remained insoluble in hot ethyl acetate whereas 4b dissolved and was separated by filtration. 3b was recrystallized from DMSO (3b, yield 54%). The ethyl acetate extract was evaporated to dryness and the crude solid recrystallized from ethanol (4b, yield 26%). 

SiC-coated or uncoated MWCNTs are dispersed in isopropylalcohol (IPA) using ultrasonic vibration for 5 min. Then the SiC-coated or uncoated MWCNTs are mixed with fine WC and cobalt powders (10 wt% cobalt) in IPA using plastic balls (10-20 mm in diameter) for 5 h. After ball milling, the IPA solution is evaporated by stirring using an electric heater and then dried at... 

Wet ball-milling is faster than dry-milling and facilitates the separation of the milling media from the charge. Its disadvantage is that the liquid must be removed, which is most economically achieved by filtration, but any soluble constituent will be removed with the liquid. If this is undesirable the alternative is to evaporate the liquid which can be effected by spray-drying if the liquid is water. Evaporation can also take place in shallow trays in ovens in this case soluble material may appear as a skin on the surface and heavy coarse particles may settle out. 

One hundred fifty grams of potassium fluoride (not the hydrate) is dried by heating over a Bunsen burner in a stainless-steel evaporating dish and is then ground for 6 to 8 hours in a ball mill containing stainless-steel ball bearings or chrome alloy steel bearings, 1 in. in diameter. 

Phenol is run into an equimolar amount of hot aqueous caustic soda in mixers. The resulting solution is heated to about 130°C and evaporated to dryness in stirred autoclaves under vacuum. This operation is sometimes carried on in heated ball mills to insure dryness as well as grinding of the resulting sodium phenate. After drying, the temperature is reduced to about 100°C, and dry carbon dioxide gas is introduced under about 6 atm (90 to 100 psi) pressure. After the desired amount of carbon dioxide is absorbed, the charge is generally heated at 150 to 170°C for several hours. 

Alternatively, ball milling of mixtures of 1 (1.00 mmol) and hydroxylamine hydrochloride (1.00 mmol) and NaHC03 (1.00 mmol) for the same times and temperatures gave 3 (100%) mixed with NaCI. The C02 escaped through a moderately tightened Teflon gasket and the water of reaction was evaporated in a vacuum. 

The nucleoside along with (Boc)20 and catalyst DMAP (amounts as stated below) were placed in the ball mill with 9-mm Pyrex beads. For small scale reactions (ca. 100-300 mg) 16-20 beads were used on gram-scale reactions as many as 25-30 were used. The mixture was ground (ca. 120-140 rpm) until the reaction was complete, as judged by TLC analysis of small aliquots scraped from the reactor and dissolved in a suitable solvent. On completion the thick oily product was washed from the apparatus using several small portions of a suitable solvent. The solvent was then evaporated and the residue was applied to a short column of silica gel. 

Boron, PCS and a-SiC powders (15wt% 30wt% 55wt%) were mixed by ball-milling for 48h using 120 gasoline as solvent to form homogenous slurries followed by evaporation of the solvent in... 

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