Quantitating the Binding Energy of Metal Ions to Langmuir-Blodgett Monolayers: The Copper(II)-Octadecylphosphonic Acid System

We report on the formation and organization of a Cu2+-complexed octadecylphosphonic acid (ODPA) monolayer formed by Langmuir-Blodgett deposition. The formation of the Cu-complexed monolayer is seen to depend sensitively on the subphase pH and Cu2+ concentration, and it is possible to form a monolayer containing the regions of complexed and free ODPA. From the pressure-area isotherm data for these monolayers, we determine the equilibrium constant and free energy of formation for the Cu2+-ODPA complex, Delta G = -22.5 kJ/mol.

Automated summary

In this study, we investigate the formation and organization of a Cu2+-complexed octadecylphosphonic acid monolayer using Langmuir-Blodgett deposition. The formation of the Cu2+-complexed monolayer is found to be sensitive to the subphase pH and Cu2+ concentration. The equilibrium constant and free energy of formation for the Cu2+-ODPA complex are determined to be Delta G = -22.5 kJ/mol.