The electronic properties and surface chemistry of passive film on reinforcement: Effect of composition of simulated concrete pore solution

The effect of composition of simulated concrete pore solution on the electronic properties and surface chemistry is investigated. Compared to NaOH, Ca(OH)2 adsorption increases donor density and vacancy flux, decreases defects diffusion coefficient and accelerates the oxidation of FeII, resulting in lower film resistance, and higher quasi-steady-state current density and roughness. Other elements, including Al, Si and S, make extracted cement pore solution (ECP) even more protective than NaOH. The FeII-rich inner layer causes the shallow donor density to increase at first and then stabilize, whereas the FeIII-rich outer layer causes the deep donor density to increase over time.