Limits to the Macroscopic Theory

The disjoining pressure in the film must be equal to the capillary pressure so that one can deduce from Eq. 11.13 an expression for the contact angle of the meniscus (Fig. 11.10a) for the partial wetting case  

Equation 11.15 reveals that Tc is smaller than H/2 -ho - the effective radius is less than half the capillary height minus the film thickness, and a transition zone between meniscus and film exists. 

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