Freeze drying depression

Figure 22, for instance, shows the behavior of a freeze-dried plug of mannitol (residual moisture 1.5%). We can see that, in comparison with the initial solution (at 10% mannitol), the thermoluminescence of the dry material is some 20 times stronger and does not follow the same pattern. The lower peak (at -152°C) is very narrow whereas the higher one (near -118°C) is substantially depressed. This is not surprising if we assume, as we have already done, that the first peak is directly connected to the water molecule itself while the second one seems to be geared to the tridimensional network of the water molecules within the crystalline lattice. 

Pentaethoxyuranium is a dark-brown, mobile liquid with a density of 1.71 g/cm3 at 25°.2 The liquid boils at 123° at 0.001 torr and is thermally stable below 170°. The compound is readily hydrolyzed and is oxidized by dry oxygen (in the presence of excess NaOC2Hs) to hexaethoxyuranium.2 Pentaethoxyuranium has a dimeric structure at room temperature as determined by freezing-point depression measurements in benzene.2 It is miscible with ethanol, diethyl ether, benzene, petroleum ether, ethyl acetate, carbon tetrachloride, chloroform, carbon disulfide, pyridine, dioxane, and nitrobenzene. The proton magnetic... 

Uses Humectant, moisturizer for personal care prods., sunscreens, soap bars, dry skin creams, shampoos, liq. soaps emollient in aq. and hydroalcoholic prods. foam modifier in detergent and shampoo systems humectant, solvent, and solubilizer for topical pharmaceuticals freezing pt. depressant Properties Pale yel. thin syrup pract. odorless sol. in water, alcohol, hydroalcoholic systems acid no. 1.0 max. iodine no. 1 max. sapon. no. 1.0 max. hyd. no. 205-225 100% cone. 

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