MONOLAYER PROPERTIES OF ALKYLAMMONIUM PERFLUOROALKANOATES

Surface pressure pi- and surface potential DELTAV area A isotherms for monolayers of alkylammonium perfluoroalkanoates of four different per fluoroalkyl chains on 4.4 M NaCl solutions were measured by the Langmu ir method and the ionizing electrode method. The phase transition pres sures pi(eq) change widely depending on the combination of hydrocarbon cation and perfluorocarbon anion lengths. Some pi-A curves of these l ong hydro-short fluoro salts exhibited two phase transition points. Fr om the surface pressure and surface potential measurements, the orient ation of the long hydro-short fluoro chain salts in the monolayer stat e was discussed.