Adsorption of a diverse set of organic vapors on the bulk water surface.
The bulk water surface is of fundamental interest to physical as well as environmental chemistry. As there is a lack of wide-ranging adsorption data from the air to the bulk water surface, a large and diverse data set of adsorption coefficients of nonionic, organic compounds has been produced with inverse gas chromatography. The 61 compounds were chosen to cover a large range of properties, considering the intermolecular interactions between the compounds and the bulk water surface, i.e., van der Waals and electron-donor/acceptor interactions. The data set gained in this work was interpreted with a linear free energy relationship (LFER) based on these intermolecular interactions. From this LFER, a general adsorption model is derived, including compound (i) and surface (surf) properties: log K(i surf/air)(m(3)/m(2)) = 0.135(+/-0.003) log K(i hexadecane/air)(gamma(surf)(vdW))(0.5) + 5.11(+/-0.15)Sigma beta(i2)(H)EA(surf) + 3.60(+/-0.28)Sigma alpha(i2)(H)ED(surf) - 8.47. This adsorption model can be used for the characterization of adsorption to any other surface. The adsorption model for bulk water surface adsorption as well as the general adsorption model can be used as prediction tools in natural or technical systems.
Roth
Christine M
CM
Swiss Federal Institute for Environmental Science and Technology (EAWAG), Ueberlandstrasse 133, Postfach 611, Duebendorf, CH-8600, Switzerland.
Goss
Kai-Uwe
KU
Schwarzenbach
René P
RP