They obtained very interesting results either in the experimental work or in the theory of the electric double layer with and without adsorbed organic species.
The adsorption of organic molecules on metal interfaces plays a very important part in the action of corrosion inhibitors, electrocrystallization modifiers, and electrode reaction modifiers. Moreover, the change in the adsorption of certain compounds with the concentration and with the electrode charge is of use in understanding their action in several biochemical reactions.
The adsorption on the mercury electrode can be studied easily and quantitatively by measuring the interfacial tension between the electrode and the electrolyte. Furthermore, it is possible to compare the adsorption behaviour of organic molecules on mercury and on solid metal electrodes when the rational electrode potentials 9 are considered.
The use of heterocyclic organic compounds as iron corrosion inhibitors was recently investigated in our laboratory. The results showed that it was necessary to carry out adsorption studies in order to understand the inhibitive effect of certain organic molecules during corrosion reactions.
In the present study the results obtained for neutral aqueous solutions of quinoline, 2-methylquinoline and 4-methylquinoline (~z-electron-deficient substances) TABLE 1 Dipole moment Ionization consta.~t (~) (pK~) Quinoline 2.2o 4.9 2-Methylquinoline 1.95 5.4 4-Methylquiuoline 2.52 5.