No abstract

The water solubilities of several polynuclear aromatic and heteroaromatic hydrocarbons have been compiled and reviewed for consistency through correlations with parameters such as surface area, molecular volume, and boiling point. The carbocycles and oxygen and sulfur heterocycles were governed by the same correlative equations, thereby indicating that these heteroatoms entered into only a limited degree of hydrogen bonding. Equations representing the nitrogen heterocycles differed from their carbocyclic counterparts by an approximately constant amount, suggesting that while the solubilizing effect of the nitrogen heteroatom may be large, it tends to remain constant within a similar series of compounds.

glio Nazionale delle Ricerche and the U.S. National Bureau of Standards on Instrumentation and Standards for the Physical and Chemical Characterization of Particulate Matter. The author acknowledges the assistance of Mr. G. Calogero for the experimental set-up and the field measurements and Mr. V. DiPalo for atomic absorption measurements. Literature Cited(1) Van De Hulst, H. C. "Light Scattering by Small Particles,"; Wiley:

Batch sorption experiments for the retention of 2,4-dichlorophenol and 2,4,5trichlorophenol by pulped wood fibers indicate that sorption is governed by the interaction of the acid form of these compounds with lignin. Measurements of fiber-water distribution coefficients over a pH range of 2 to 12 demonstrate that chlorophenolate ions do not sorb to the solid phase, and the interaction between the neutral form of the compound and lignin is p'nmafily responsible for the retention within this pH region. This was confirmed by experiments using lignin and cellulose model particles and pulp fibers of various lignin contem.The results have led to the development of an equation that relates the overall fiber-water distribution coefficient to the ionization of the phenol, the lignin mass fraction of the fiber, and a lignin-water distribution coefficient which can be estimated with a linear free-energy relationship.Modeling the fiber-water transfer of chlorophenols based on the dominance of the hydrophobic interactions was successful in the treatment of concentration, temperature, and inorganic salt effects. Sorption isotherms were shown to be linear and to have no dependency on phenol cosolutes at concentration levels common in bleaching. Distribution coefficients demonstrated only a slight dependency on temperature and inorganic salt concentrations which could be pre_cWxlfrom the solute's heat of aqueous dissolution and Setschenow constants, respectively. Measurements also indicate that sorption is unaffex:tedby fiber surface area and concentration, but do show dependency on the concentration of colloidal materials which appear to be the result of third-phase sorption.

Water solubilities, octanol/water partition coefficients and vapor pressures were measured for a variety of commercial phthalate esters, several of which were mixtures. The results provide insight into the applicability of the procedures, which were developed for pure compounds, to more complex industrial products and formulations.