Figure 17.
(a) Drop coalescence between a glycerol drop and a bath of the same liquid (76% v/v, μd = 54 mPa∙s, and ρd = 1210 kg/m3) in a low-viscosity oil (μo = 1.75 mPa∙s, and ρo = 8.4 kg/m3) in a Hele-Shaw cell (D = 1.25 mm). Top: without Span 80. Bottom: with Span 80 (0.015% w/w). (b) Linear scale plot of r(t) with different σ values (blue numbers: mN/m). (c) Normalized plot of (b). Here, tc = μdD/σ. Inset: Averaged speed of the neck growth. The solid black line in the inset represents the fitted slope for α = 0.7. Adapted from [38].