FABRICATION OF IrO_2-pH MICROELECTRODE AND ITS APPLICATION IN STUDY OF CHEMICAL MICRO-ENVIRONMENT AT STEEL/CONCRETE INTERFACE

采用电化学阳极氧化和高温碳酸盐氧化两种方法制备IrO2 - pH微电极 ,其特点是对氢离子响应快、线性范围宽、机械性能好、具有长期稳定性 .考察了该电极的 pH响应特性、化学成分、机械性能等 .结果表明 ,这种IrO2 -pH微电极适用于钢筋 /混凝土界面 pH值的原位测量The corrosion behavior of the reinforcing steel has a close dependence on the chemical micro-environment at the steel/concrete interface.In this paper,a kind of IrO 2-pH microelectrode was prepared by anodic electrochemical oxidation and thermal oxidation in carbonate.In the latter case,IrO 2 electrode showed fast linear response,wide linear range(pH 0～14),satisfying mechanical property and long-term stability.The formation of IrO 2 electrode was characterized and the potential response to H + was tested to explore the optimum condition of fabrication of the IrO 2 electrode.The IrO 2-pH electrode was applied for the in-situ measurement of pH at the steel/concrete interface.国家自然科学基金资助项目 (资助号 :5 98710 43