Effect of Pentaerythritol Glycoside on Performance of Passive Film Formed on Steel Rebar in Saturated Ca(OH)2 Solution Containing 3.5%NaCl

Abstract

The effect of PG(pentaerythritol glycoside) on the performance of the passive film on steel rebar in Ca(OH)2saturated solution containing 3.5%NaCl, which was designed to simulate solutions in concrete pores, was investigated by mean of polarization curve measurement, MottSchottky analysis technique and surface analysis. The results showed that the PG could enhance the stability of the adsorption film formed on the metal surface. The curves of Csc-2vs E of the steel rebar electrodes follow a linear Mott-Schottky(M-S) relationship with a positive slope in the range of potential from-0.5 to-0.1 V(vs SCE) in the M-S measurements, suggesting the passive film formed on the steel rebar surface was n-type semi-conductor. Moreover, with increasing concentration of inhibitor, the carrier density in passive film decreases, indicating that the passive film formed on steel rebar surface in the presence of PG was more compact and stable rather than that in the absence of inhibitor, and the corrosion resistance of passive film is gradually enhanced.