Sessile bubble force balance

Figure 27.2 Force balance at the three phase line (a) a sessile water droplet and (b) a sessile air bubble.

Modern methods of measuring the surface tension include the pendant drop method, the sessile drop method, and others (7,8,15). These methods depend on the shape of a drop of the polymer or a bubble in it, and on the balance of surface tension and gravitational forces see Figure 12.3 (8). 

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