Crystal charge material

A 600-ml. steel reaction vessel (Note 1) is precooled before loading by filling it between one fourth and one half full of methanol and Dry Ice. After removal of the methanol and Dry Ice, the autoclave is charged with 120 g. (176 ml., 1.76 moles) of isoprene (Note 2), 113 g. (80 ml, 1.76 moles) of liquid sulfur dioxide, 88 ml. of methanol, and 4 g. of hydroquinone. The vessel is sealed, heated slowly to 85°, and maintained at that temperature for 4 hours. It is then cooled, the sulfone removed, the bomb rinsed with methanol, and the combined product and washings are treated hot with 5 g. of Norite. The filtered solution is concentrated to a volume of 250-300 ml., and the sulfone is allowed to crystallize. The material is filtered and washed with 50 ml. of cold methanol. Recrystallization from methanol (20 ml. per 25 g. of sulfone) yields 140-150 g. of thick, colorless plates. Concentration of the mother liquors raises the total yield to 182-191 g. (78-82%) (Note 3), melting at 63.5-64° (Note 4). 

As with nematic liquid crystals, cholesteric materials may show electrooptical effects which are related to the orientation of the molecules by the hydrodynamic flow induced by a space charge motion in a material with a rather large conductivity. The sign and magnitude of Ae are not very important for the electrohydrodynamic phenomena, since they are induced by the anisotropy of the electrical conductivity. 

Soluble Salt Flotation. KCl separation from NaCl and media containing other soluble salts such as MgCl (eg, The Dead Sea works in Israel and Jordan) or insoluble materials such as clays is accompHshed by the flotation of crystals using amines as coUectors. The mechanism of adsorption of amines on soluble salts such as KCl has been shown to be due to the matching of coUector ion size and lattice vacancies (in KCl flotation) as well as surface charges carried by the soflds floated (22). Although cation-type coUectors (eg, amines) are commonly used, the utUity of sulfonates and carboxylates has also been demonstrated in laboratory experiments. 

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