Capillarity and Surface Forces (Liquids) - Surface and Colloid Chemistry: Principles and Applications - page 38

table 2.4
Interfacial tensions IFt between
Water and organic liquids (20°c)

Water/organic liquid IFt [mn/m]

n -Hexane 1.0

n -Octane 50.8

CS 2 48.0

CCl 4 45.1

Br-C 6 H 5 38.1

C 6 H 6 35.0

NO 2 -C 6 H 5 26.0

Ethyl ether 10.7

n -Decanol 10

n -Octanol 8.5

n -Hexanol 6.8

Aniline 5.9

n -Pentanol 4.4

Ethyl acetate 2.9

Isobutanol 2.1

n -Butanol 1.6

The drop weight method is carried out by using a pump to deliver the water
phase into the oil phase (or vice versa, as one finds suitable). The water drops sink
to the bottom of the oil phase. The weight of the drops is measured (by using an
electrobalance), and IFT can be calculated. Accuracy can be very high by choos-
ing the right kind of setup. The drop shape (pendant drop) is most convenient if
small amounts of fluids are available and extreme temperatures and pressures are
involved. Modern digital image analyses also makes this method very easy to apply
in extreme situations.

2.8 aPPlIcatIonS
The role of surface tension of liquids is found in many important systems. The cap-
illary vise is found to play an important role in many everyday processes (such as
washing and cleaning, plants, etc.).