Dynamic interfacial tension droplet frequency

Figure 11. Dynamic interfacial tension vs. droplet frequency.

Figure 26. Dynamic interfacial tension vs. droplet frequency of various surfactant solution—oil systems (l).

Of the various other methods we mention a few of a more dynamic nature. From wave damping yiw) can in principle be obtained co is the frequency of the applied wave. See sec. 3.6g. Guido and Villone ) proposed a procedure to obtain interfacial tensions from the rate at which shear-deformed droplets retracted to their equilibrium spherical shape. De Hoog and Lekkerkerker ) determined very low interfacial tensions by following the initial state of the Rayleigh break-up of elongated drops. Although these methods are unlikely to develop into routine procedures, they demonstrate how wide the methodical spectrum is. 

Here, (pi is the volume fraction of droplets with radius i ,. The volume-averaged radius can be used instead of the distribution if the polydispersity is less than 2.3. The fit to G data for a 6.5% dispersion of poly(ethylene terephthalate) in a linear fluoropolymer at 300 °C, with an average droplet radius of 5.4 /rm, is shown in Figure 14.4, where the data are plotted as the ratio of the storage modulus of the blend to that of the matrix polymer. The peak reflects the frequency regime where the interfacial dynamical response is sensitive to interfacial tension. Interfacial tension acts like an elastic stress, so the major contribution of the interface is in G . The interfacial tension of the blend estimated from standard equations is about... 

---