Wetting energy

Wetting energies Wet-web strength Whale Oil Whatman 3 MM Whatman No. 1 Wheat... 

The wetting energies give repulsive forces exceeding that of the van der Waals attractive force under certain conditions. The combined van der Waals and wetting force is given by equation 7 in which h is the distance perpendicular to the interface that the particle has moved from its equilibrium position. 

Energy of Immersional Wetting See Work of Immersional Wetting. Energy of Separation See Work of Separation. 

Contact angle (6) and wetting energy (7 cos 6) (erg cm ) to various polymer films ... 

Proteins act in a similar way to polymeric stabilizers (steric stabilization). However, molecules with compact structures may precipitate to form small particles that accumulate at the oil/water interface. These particles stabilize the emulsions (sometimes referred to as Pickering emulsions) by a different mechanism. As a result of the partial wetting of the particles by the water and the oil, they remain at the interface. The equUibrium location at the interface provides the stability, since their displacement into the dispersed phase (during coalescence) results in an increase in the wetting energy. 

From the above discussion, proteins clearly act as stabilizers for emulsions by different mechanisms depending on their state at the interface. If the protein molecules unfold and form loops and tails they provide stabilization in a similar way to synthetic macromolecules. Conversely, if the protein molecules form globular structures, they may provide a mechanical barrier that prevents coalescence. Finally, precipitated protein particles located at the oil/water interface provide stability as a result of the unfavourable increase in wetting energy on their displacement. Clearly, in all cases, the rheological behaviour of the film plays an important role in the stability of the emulsions (see below). 

FIGURE 2.2 Left The vertical position of a spherical particle intersecting a flat interface is parametrized hy the angle 9. Right Plot of the wetting energy. Equation 2.1, as a function of 9. 

Wetting Energies (mN/m) for Paracetamol Form I (Molecules Optimized in Bulk Structure)... 

Figure 3.3 gives a comparison of the COSMO results and H2O experimental wetting energies from the work of Heng et al. - using the structures proposed by Haisa... 

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