Activation Energy de Vries Theory

The created surface area of the edge, which can be modeled as a surface of revolution, formed by revolving a semicircle around the symmetry axis, equals  

Assume first that the interfacial tensions of the curved and planar parts are the same. The free energy balance of the nucleation pore in a liquid film states that  

Consider again eqn. (7.25). The first term on the right-hand side is proportional to the hole surface area and is the interfacial tension contribution. The second term is proportional to the hole perimeter and is therefore the line tension contribution. (The third term is constant for constant film thickness b and can be incorporated into the pre-exponent.) The alternative way to model the film rupture is to present the free energy of the nucleation pore as the sum of the line and surface tension terms  

Here y = a(n - 2)b is the line tension the coefficient 2 on the second term accounts for the two sides of the film. The free energy has a maximum at the critical hole radius a  

The treatment of the hole nucleation in terms of the interfacial and line tensions is equivalent to the surface area analysis presented above. It has an advantage, however, that the line tension can be considered as a phenomenological parameter which is not necessarily equal to o(ji — 2)b. The analysis of the film rupture in terms of surface and line tensions was developed by several groups.  

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