Surface behaviour of tetrapropylammonium cation at the mercury/solution interface measured by use of controlled convective adsorptive accumulation

摘要: Using drop time technique with long drop times and a controlled convection of the solution the surface tension data of Hg with tetrapropylammonium perchlorate in 0.1 mol l-1 NaClO4 in the concentration range 4 . 10-6 - 3 . 10-3 mol l-1 have been obtained. The corresponding adsorption parameters have been evaluated from the Frumkin isotherm both at constant potential E and at constant charge q. Both E and q could be chosen as an independent electrical variable. The maximum free adsorption energy amounts to approx. -36.5 kJ mol-1. The congruence of adsorption isotherms with respect to E and with respect to q was very well fulfilled for the surface coverage Θ ⪬ 0.6-0.7.