Chapter 5
and 6.0. At pH 6.0 (Figure 5.11), the top of the oil layer is clean oil. At the bottom
of the oil layer is oil-in-water emulsion with relatively low oil concentration. At pH
8.5, the emulsion has similar result to that at pH 6.0. At pH 5.0 (Figure 5.10), the
top of oil layer is clean oil, but in this case the bottom of the oil layer is oil with a
few drops of dispersed water. The water layer is also almost clean. Emulsion
samples at pH 5.0 and 6.0 have different emulsion type. Thus the original
oil-in-water emulsion remains stable at pH 6.0, but not at pH 5.0.
1. Top of the oil layer
3. Near oil∕water interface
2. Middle of the oil layer
4. Water layer
(The scale bar is 20 μm)
Figure 5.11 24 h emulsion sample adding HCI (equilibrium pH 6.0)
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