ABSTRACT
The concentration of the electrolyte also plays an important role in determining whether the foam collapses completely, or arrives at a drainage equilibrium. Fig. 27 shows the variation in foam height with time for two systems that differ only in the electrolyte concentration. The initial foam height is 4 cm and the values of the other parameters used are: ρ=1000 kg/m3, µ=1 cP, ψs=19 mV, R0=0.2 mm, Ah=3.7×10−20, σ=40 mN/m, and G=0.0005 m/s. The foam with cel=0.003 M equilibrates at a height of about 1.85 cm, whereas the foam with cel=0.007 M collapses completely. This can be ex-
