用于混凝土中钢筋腐蚀监测的固态Ag/AgCl参比电极的制作及其性能

Fabrication and Properties of Ag/AgCl Solid Reference Electrode for Monitoring Corrosion of Reinforcing Steel Bars of Concrete

为了制备可用于混凝土中钢筋腐蚀监测的参比电极,先在三电极体系下采用恒电流阳极氧化法获取Ag/Ag Cl探针,再通过凝胶电解质封装制备了固态Ag/Ag Cl参比电极。将其用于碱性混凝土孔隙液中,研究了其Nernst响应特性和电位稳定性,并探讨了其抗各种环境因素(p H值、SO2-4、温度、电化学极化)干扰的能力。结果表明:固态Ag/Ag Cl参比电极具有良好的Nernst响应;当p H值小于12时,p H值对参比电极电位影响较小,当p H值大于12时p H值每增加1,电极电位下降约50 m V;电极的温度响应特性与抗SO2-4干扰和抗极化能力较好,适用于混凝土中钢筋腐蚀的监测。

Ag/AgCl probe was prepared by the anodic oxidation of Ag rod under constant current in a three-electrode electrochemical instrument.Resultant Ag/AgCl probe was then encapsulated to afford Ag/AgCl solid reference electrode used for monitoring the corrosion of the reinforcing steel bars of concrete.The Nernst response feature and potential stability of the as-fabricated Ag/AgCl solid reference electrode in an alkaline concrete pore fluid were investigated,and its ability to resist the interferences of various factors such as chloride ion,sulfate ion,pH value,temperature and polarization was examined.It was found that the asfabricated electrode had good Nernst response ability.When the pH value was less than 12,the pH value had a marginal effect on the potential of the electrode.However,when the pH value was more than 12,the rise of pH value by 1 led to the decrease of the electrode potential by 50 mV.Besides,the as-fabricated Ag/AgCl solid reference electrode exhibited good temperature response capacity as well as good ability to resist sulfate ion interference and polarization,showing promising potential for monitoring the corrosion of the reinforcing steel bars of concrete.