Apparent hydration numbers of alcohols in aqueous solution

1972 ◽  
Vol 76 (11) ◽  
pp. 1660-1666 ◽  
Author(s):  
Charles H. Spink ◽  
John C. Wyckoff
Keyword(s):  
Aqueous Solution ◽  
Hydration Numbers

Are all polar molecules hydrophilic? Hydration numbers of nitro compounds and nitriles in aqueous solution

2014 ◽  
Vol 16 (26) ◽  
pp. 13262-13270 ◽  
Author(s):  
Naoya Sagawa ◽  
Toshiyuki Shikata
Keyword(s):  
Aqueous Solution ◽  
Nitro Compounds ◽  
Polar Molecules ◽  
Hydration Numbers ◽  
Hydrophilic Hydration

Typical highly polar nitro compounds and nitriles should be classified ashydroneutralcompounds because of their hydration numbers of zero.

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

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