FATTY ACID MONOLAYERS IN EXPANDED STATE .2. EFFECT OF COMPRESSION VELOCITIES

In order to make clear physicochemical states of monolayers, the effect of compression velocities on the monolayers of myristic and stearic acids was investigated. It was observed that the surface pressure vs. area (π vs. A) curves of the myristic acid monolayer were markedly affected by compression velocities, whereas those of the stearic acid monolayer were virtually the same for various compression velocities. The effect of compression velocities on the myristic acid monolayer was explained by its desorption; this was proved theoretically by a desorption mechanism by which the molecules dissolve into the underlying solution and then diffuse away from the surface. The π vs. An curve, where An is the net area per molecule, for myristic acid was satisfactorily described by the equation of state developed in Part I of this series. © 1969.