In addition to 18-MEA, several free fatty acids are known to occupy the cuticle surface . In order to test the role that these molecules play on the hair surface morphology and its interactions with surrounding molecules, three additional models were created where stearic and palmitic acid molecules were added in a 1:1 molar ratio to each side (90 in total) of each of the three hair slab models described in subsection 2.1.1, for a total of six systems. To take into account the effect of wetting/solvation of the cuticle surface 12,000 water molecules were added to replicas of each of the six previously described systems, for a total of 12 systems. All adsorbents were added using the Disordered System Builder.