Solubility terminology

Surface activity is not limited to aqueous systems, however. AH of the combiaations of aqueous and nonaqueous phases are known to occur, but because water is present as the solvent phase in the overwhelming proportion of commercially important surfactant systems, its presence is assumed in much of the common terminology of industry. Thus, the water-soluble amphipathic groups are often referred to as solubilizing groups. 

Dietary fiber is the accepted terminology ia the United States for nutritional labeling. Total dietary fiber (I DF) and its subfractions, insoluble dietary fiber (IDF) and soluble dietary fiber (SDF), are defined analytically by official methods (3—5). 

In a fundamental sense, the miscibility, adhesion, interfacial energies, and morphology developed are all thermodynamically interrelated in a complex way to the interaction forces between the polymers. Miscibility of a polymer blend containing two polymers depends on the mutual solubility of the polymeric components. The blend is termed compatible when the solubility parameter of the two components are close to each other and show a single-phase transition temperature. However, most polymer pairs tend to be immiscible due to differences in their viscoelastic properties, surface-tensions, and intermolecular interactions. According to the terminology, the polymer pairs are incompatible and show separate glass transitions. For many purposes, miscibility in polymer blends is neither required nor de-... 

Increase in mass-transfer rate per unit area. As stated above, agitated gas-liquid contactors are used, in general, when it is necessary to deal with sparingly soluble gases. According to the terminology of the film theory, absorption is then controlled by the liquid resistance, and agitation of the liquid phase could increase the mass-transfer rate per unit area. As will be... 

The initiator is present in the water phase, and this is where the initiating radicals are produced. The rate of radical production if, is typically of the order of 1013 radicals L-1 s-1. (The symbol p is often used instead of Rj in emulsion polymerization terminology.) The locus of polymerization is now of prime concern. The site of polymerization is not the monomer droplets since the initiators employed are insoluble in the organic monomer. Such initiators are referred to as oil-insoluble initiators. This situation distinguishes emulsion polymerization from suspension polymerization. Oil-soluble initiators are used in suspension polymerization and reaction occurs in the monomer droplets. The absence of polymerization in the monomer droplets in emulsion polymerization has been experimentally verified. If one halts an emulsion polymerization at an appropriate point before complete conversion is achieved, the monomer droplets can be separated and analyzed. An insignificant amount (approximately <0.1%) of polymer is found in the monomer droplets in such experiments. Polymerization takes place almost exclusively in the micelles. Monomer droplets do not compete effectively with micelles in capturing radicals produced in solution because of the much smaller total surface area of the droplets. 

Note Because the term resin is so broadly used as to be almost meaningless, it would be desirable to restrictit application to natural, organ-soluble. hydrocarbon-based pioducts derived from frees and shrubs. But in view of the tendency of inappropriate terminology to gel irreversibly, it is a losing battle to attempt to replace synthetic resin with the more precise synthetic polymer. See also Gums and Mucilages and Resins (Natural). 

Rate Measures for Interfacial Processes Terminology used for reporting rate data can be confusing. Normally rate data are reported on a volumetric basis with transfer rate and effective area combined. For example, kLa denotes mass-transfer data per unit volume. The L subscript means it is referenced to the molar concentration difference between the interface and the bulk liquid. This is commonly used on data involving a sparingly soluble (high relative volatility) component. Note that the lowercase k means the data deal only with the resistance in the liquid phase. 

FIGURE 10 Terminologies for drug solubility. The drug solubility is qualitatively described depending on how much solvent is required to solubilize 1 g of the drug. 

To calculate AWm (the enthalpy of mixing) the polymer solution is approximated by a mixture of solvent molecules and polymer segments, and AW is estimated from the number of 1,2 contacts, as in Section 12.2.1. The terminology is somewhat different in the Flory-Huggins theory, however. A site in the liquid lattice is assumed to have z nearest neighbors and a line of reasoning similar to that developed above for the solubility parameter model leads to the expression... 

By the treatment of Cross and Bevan cellulose, or cellulose isolated by some other purification procedure, with 17.5% sodium hydroxide under carefully controlled conditions, and then carefully washing, a fibrous product is obtained which is termed a-cellulose. As previously indicated, Cross and Bevan used this procedure for determining the purity of cellulose preparations. This product upon further similar treatments continues to lose weight, indicating the empirical nature of the treatment and terminology. Upon acidif3ring the alkaline filtrate a precipitate is formed. This fraction is known as /3-celIulose. The alkali-soluble extract which remains in solution after acidification of the solution is termed -y-cellulose. Since continued extraction of a-cellulose with caustic causes the formation of increasing amounts of /3-and y-cellulose, the incomplete removal of these fractions in one operation or the conversion of o-cellulose into 0- and -y-cellulose is indicated. In practice... 

Bieri, J. G., and McKeima, M. C. (1981). Expressing dietary values for fat-soluble vitamins Changes in concepts and terminology. Am. J. Clin. Nutr. 34,289-295. 

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