Anionic surfactant induced desorption of a cationic surfactant from mica

The adsorption and desorption of a cationic surfactant, didodecyldimethylammonium bromide, from water onto a mica surface have been investigated using neutron reflectivity. The surfactant was observed to adsorb strongly as a bilayer that was tenacious to a sustained water wash, but on the addition of an anionic surfactant, sodium dodecyl sulfate, at its critical micelle concentration complete desorption was observed.