Other Surface Properties of Liquids

There are a variety of other surface chemical properties of liquid surfaces. This arises from the fact that different forces stabilize liquids. Since these are out of scope of this book, only a few important examples will be mentioned. 

Surface waves on liquids Liquid surface, for example, on oceans or lakes, exhibits waves formation when strong winds are blowing over it. It is known that such waves are created by the wind 

Oil and water do not mix this is an everyday observation. Main reason is oil is insoluble in water, and vice versa. At the oil-water interface, one will thus have interfacial surface forces. In this chapter, the methods in which one can indeed disperse oil in water (or vice versa) will be described. The analyses of the IFT, which exists at any oil-water interface, will be described. In the literature, the IFT, 7ab between two liquids with and Yb has been described in much detail (Adamson and Cast, 1997 Chattoraj and Birdi, 1984 Miqueu et al., 2011 Peng et al., 2011 Somasundaran, 2006). An empirical relation was suggested (Antonow s rule) by which one can predict the surface tension Yab- 

The prediction of Yab oni this rule is approximate but found to be useful in a large nnmber of systems (such as alkanes water), with some exceptions (such as water butanol) (Tables 1.3 and 1.4). For example. 

However, for general considerations, one may only use it as a reliable guideline and when exact data are not available. The Antonow rule can be understood in terms of a simple physical picture. There should be an adsorbed film or Gibbs monolayer of substance B (the one of lower surface tension) on the surface of liquid A. If we regard this film as having the properties of bulk liquid B, then Ya(b) is effectively the IFT of a duplex surface and would be equal to [Ya(B) + Yb(a)]-Measurement of IFT (between two immiscible liquids)  

It is a well-known adage that oil and water do not mix. However, it will be shown that, by changing the interfacial forces at the oil-water boundary, one can indeed disperse oil in water (or vice versa). At the oil-water interface there exists interfacial tension (IFT), which can be measured by some of the methods mentioned earlier (e.g., by drop weight, pendant drop, or Wilhelmy plate). 

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