Surface tension component method model

The surface tension component method assumes that surface tension can be partitioned into different components, which address different intermolecular interactions individually. The overall surface tension will be the sum of all the components according to the linear free energy relationship. In the original Fowkes method [14], only the dispersion interaction is considered. The component method has been subsequentiy extended to include polar component and later divided the polar component into dipolar interaction and H-bonding interaction. The vOCG model appeared as a refined version of the surface tension component methodology. It assumes the existence of both additive and nonadditive components. The Lifshitz-van der Waals component (/ ) is additive, and the electron donor and acceptor components (7 and 7" ) are nonadditive. The solid surface tension (7sv) can be calculated by using three Uquids with known y, y and y values. Since this is a semiempirical approach, the calcu-... 

In addition to the methods discussed above, there are a few other solid surface tension determination methods, such as the Wu method [29, 30] and the Schultz methods [31, 32], which also fall into the category of partitioning surface tensions into independent components. Wu used the harmonic means to describe the interfacial surface tension instead of the geometric mean, based on a few slightly different assumptions to derive the equations for Wu s model. The Schultz methods can be considered as a special case of the extended Fowkes method. The contact angle of a polar liquid (usually water) on the solid is conducted in another nonpolar liquid medium (e.g., pure hydrocarbon compounds), or the contact angle of a nonpolar liquid on the solid is measured in another polar liquid medium. 

Values of Yq are often taken to be the surface tension of the pure components, Y and have also been obtained by iterative procedures. Figure 4a shows a typical plot of Y as a function of x for a binary slag and the individual x Yi contributions have also been included. These methods work well for certain slag mixtures but break down when surface-active constituents, such as P205 are present. These components migrate preferentially to the surface and cause a sharp decrease in the surface tension and consequently only very small concentrations are required to cause an appreciable decrease in Y. Thus some unreported or undetected impurity could have a marked effect on the surface tension of the slag and thereby produce an apparent error in the value estimated by the model. In this respect surface tension differs from all the other physical properties which are essentially bulk properties. 

The surface tension, interfacial tension and adhesion phenomena will be discussed, and a new correlation for the molar parachor will be presented, in Chapter 7. The calculation of the interfacial tension from the surface tensions of the components will also be discussed, and shown to be in need for significant improvements. In this context, an introduction will also be provided to advanced numerical simulation methods that are becoming increasingly useful in modeling the interfacial phenomena and phasic behavior of polymer-containing systems. 

Owens-Wendt-Rabel-Kaelble (OWRK) method. Owens and Wendt [19] modified the Fowkes model by assuming that solid surface tension and liquid surface tensions are composed of two components, namely, a dispersion component and a hydrogenbonding component. The nondispersive interaction was included into the hydrogenbonding component. Nearly at the same time, Rabel [20] and Kaelble [21] also published a very similar equation by partitioning the solid surface tension into dispersion and polar components. Subsequent researchers called this as the OWRK method, and ysv and jiv can be expressed as... 

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