一种可用于混凝土内部固态MnO_2参比电极研究

Studies on the Performance Characteristics of Manganese Oxide Reference Electrode for Concrete Environments

研发一种可用于混凝土内部固态MnO2参比电极。电极主要材料为MnO2胶体、Ca(OH)2胶体和高纯度石墨粉末。调整材料质量配比制备A、B和C类固态MnO2参比电极,配置模拟混凝土内部环境的混凝土模拟液进行MnO2参比电极对比试验研究。通过电位波动限值分析MnO2参比电极不合格率;通过电极电位值相对标准误差分析其重现性、稳定性、温度、碳化和氯离子敏感性五项性能;给定各项性能权重值进而计算综合分数值,评定MnO2参比电极综合性能。研究表明:A、B和C类MnO2电极具有较好的性能,其重现性性能低于其稳定性、温度、碳化和氯离子敏感性。C类MnO2电极各项性能以及综合性能最优,A、B类次之。所研发的固态MnO2参比电极对发展混凝土结构无损检测和长期健康监测电化学传感器技术具有重要意义。

Manganese oxide （ MnO2 ） reference electrodes are presented which can be used for concrete environments. The materials of MnO2 electrodes mainly are MnO2 gels, Ca （ OH ） 2 gels and high purity graphite powders. Three kinds of MnO2 electrodes with different ratio of the main materials, namely A, B and C, are accomplished. Their comparable performance characteristics are evaluated in a synthetic concrete pore solution which is corresponding to the concrete environments. The reject rates of MnO2 electrodes are gotten by setting the permitted variance of the electrode’s potentials. Their properties expressed as the relative standard error of sensorial potential are analyzed, such as electrochemical reproducibility, electrochemical stability, and sensitivities of temperature, carbonization and chloride ion. Their comprehensive properties are compared by calculating each electrode’s comprehensive value which is based on the reject rate,the relative standard error and the corresponding weight value. The experimental results show that：at first,MnO2 electrode A,B and C have good performances,and the reproducibility of each electrode is lower than its stability,sensitivities of temperature,carbonization and chloride ion. The second, above each performance and comprehensive property of MnO2 electrode C are better than MnO2 electrode A and B. The presented MnO2 reference electrodes are essential to the developing of chemistry sensor technique in nondestructive inspection of concrete and long-term health monitoring of concrete.