Mixed Monolayers of Long Normal Chain Fatty Acids with Long Normal Chain Fatty Alcohols

Abstract

Abstract The mixed monolayers of long normal chain fatty acids with long normal chain fatty alcohols were studied at various compositions and temperatures. The π-A curves of these systems were measured and the two-dimensional phase diagrams were obtained. The partial molar enthalpy change from the expanded to the condensed state was calculated. It was observed that the phase diagram and enthalpy change of these systems are similar to those previously obtained from the mixed monolayers of long normal chain fatty acids. The miscibility of these systems changes with the increase in the difference of the chain length, as in the systems of fatty acids. It was concluded that the monolayer behavior of the mixed system of an acid and an alcohol is analogous to that of the mixed system of the acid and an acid which contains one more carbon atom in a molecule than the corresponding alcohol.