Dyne solvent soluble

Solvent Mol. Wl. BP C 760 mm Hg Specific Gravity (20 C) Viscosity cPat 25 C Surface Tension (25 C) dynes/cm Solubility Solvent in water, s/lOOa... 

Dark reddish-brown liquid the only nonmetallic element that is a liquid at ambient temperatures strong disagreeable odor volatilizes density 3.12 g/mL at 20°C vapor density 7.59 g/L refractive index 1.6475 boils at 58.8°C solidifies at -7.2°C vapor pressure 64 torr at 0°C and 185 torr at 22°C critical temperature 315°C critical pressure 102 atm critical volume 127 cm /mol surface tension 39.8 dynes/cm at 25°C electrical resistivity 6.5 x 10i°ohm-cm at 25°C sparingly soluble in water (2.31 g/lOOg at 0°C and 3.35 g/lOOg at 25°C) soluble in common organic solvents. 

Finally Papkov [52] observed that the surface tension of the solvent is a further factor influencing the solubility of cellulose esters. This worker established that the best solvents from a series of liquids resembling each other chemically, e.g. in a homologous range, were characterized by a moderate, optimum surface tension. Liquids having higher or lower surface tensions than this optimum value are worse solvents. The rule is also valid for mixtures. Thus a 50 50 acetone-water solution with a surface tension a = 30.4 dyne/cm caused only a weak swelling of... 

Asphaltenes are dark brown to black friable solids that have no definite melting point, and when heated, usually intumesce, then decompose leaving a carbonaceous residue. They are obtained from petroleums and bitumens by addition of a nonpolar solvent (such as a hydrocarbon) with a surface tension lower than 25 dynes cm-1 at 25°C (such as liquefied petroleum gases, the low-boiling petroleum naphthas, petroleum ether, pentane, isopentane, and hexane) but are soluble in liquids having a surface tension above 25 dynes cm-1 (such as pyridine, carbon disulfide, carbon tetrachloride, and benzene) (6, 7). 

Properties Colorless, volatile, mobile liquid. Hygroscopic, aromatic odor, burning and sweet taste. Bp 34.5C, fp -116.2C, d 0.7147 (20/20C), surface tension 17.0 dynes/cm (20C), refr index 1.3526 (20C), viscosity 0.00233 cP (20C), vap press 442 mm Hg (20C), specific heat 0.5476 cal/g (30C), flash p -49F (-45C), autoign temp 356F (180C), latent heat of evaporation 83.96 cal/g at bp, electric conductivity 4 X 10 3mho/cm (25C), bulk d 6 lb/gal (20C). Soluble in alcohol, chloroform, benzene, solvent naphtha, and oils slightly soluble in water. 

For an atom in the enzyme or the substrate to interact with the solvent it must be able to form Van der Waals contact with water molecules. The accessible surface area of an atom is defined as the area on the surface of a sphere, radius R on each point of which the centre of a solvent molecule can be placed in contact with the atom without penetrating any other atoms of the molecule (Fig. 12). R is the sum of the Van der Waals radii of the atom and solvent molecule [27]. There is a linear relationship between the solubility of hydrocarbons and the surface area of the cavity they form in water [28]. It has been estimated that the hydrophobicity of residues in proteins is 100 J/mole/A of accessible surface area [29]. The surface tension of water is 72 dynes/cm so to form a free surface area of water of 1 A costs 435 J/mole/A. The implication is that the free energy of cavity formation in water to receive the hydrophobic group is offset by favourable interactions (dispersion forces) between the solute and water. 

Surface tension, dynes cni Figure 2.3.22. Hildebrand solubility parameter vs. surfaee tension for four groups of solvents. 

Sulfolane is a very high boiling-point, colorless liquid with a very high viscosity (10.3 centipoises) and medium surface tension value (35.5 dynes/cm). Although the structure and reactions of sulfolane show the molecule to be very polar in nature, no Hansen solubility parameters have been reported in the literature for this solvent. Sulfolane is miscible with water and many organic solvents. 

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