ELECTRICAL-PROPERTIES OF SOME ADSORBED FILMS AT THE WATER AIR INTERFACE

Measurements of surface potential ( DELTA V) and surface tension ( DELTA sigma ) of aqueous solutions of acetic acid, chloro-, dichloro-, trichloroacetic acid, and alcohols (methanol, ethanol, 2,2,2-trifluoroethanol) were used for the determination of effective dipole moments ( mu OVER BAR ) and their separate components. For this purpose, the Helmholtz equation (in the form presented by Demchak and Fort) have been applied. The contributions from the reorientated water molecules ( mu OVER BAR //1/e//1), and from hydrophilic ( mu OVER BAR // phi //-//C//O//O//H, mu OVER BAR // phi //-//O//H) and hydrophobic ( mu OVER BAR // phi //-//C//H//3, mu OVER BAR // phi //-//C//H//2//C//l, mu OVER BAR // phi //-//C//H//C//l//2, mu OVER BAR // phi //-//C//F//3) groups and the local dielectric permittivity in the vicinity of these groups were calculated.