Hydrophobicity reinterpreted as ‘minimisation of the entropy penalty of solvation’

Abstract

Alkanes are simple examples of hydrophobic molecules. Hydrophobic, loosely translated, means ‘water hating’. Many fascinating physical phenomena are today explained by appealing to this concept. The facts about alkanes in water are simple. At room temperature and pressure, simple alkanes are ca. 100 times less soluble in water than in benzene. Many people say that this is because the alkanes are ‘hydrophobic’, but do the alkanes really ‘hate’ the water? In the view of this author, the experimental data are unequivocal on this point: the simple alkanes ‘like’ the water. It is the water which ‘hates’ the alkanes. This view is supported further by the high solubility of water in liquid methane and simple two-dimensional models.