The micellization releases water molecules which initially solvate the hydrophilic head groups. The release of these waters greatly increases the entropy.
Does entropy increase during micelle formation?
Compared to the increase of entropy of the surrounding water molecules, this hydrophobic interaction is relatively small. The water molecules are highly ordered around the hydrocarbon chain. The CMC decreases while the length of the alkyl chain increases when all the hydrocarbon chains are hidden inside micelles.
Is enthalpy of micelle formation negative?
It was found that the hydrophilic part has a major contribution at lower temperatures but at higher temperatures it gives a minor contribution, and that the hydrophilic part of ΔHm is always positive having a minimum around 40°C, while the hydrophobic part is always negative and decreases monotonically with temperature ...
