Electrochemical Characterization and Inhibiting Mechanism on Calcium Leaching of Graphene Oxide Reinforced Cement Composites
Electrochemical Characterization and Inhibiting Mechanism on Calcium Leaching of Graphene Oxide Reinforced Cement Composites
复制标题
氧化石墨烯增强水泥复合材料钙浸出的电化学表征及抑制机理
DOI：
10.3390/nano9020288
复制
发表时间：
2019-02-01
期刊：
影响因子：
5.3
通讯作者：
Feng, Gan-Lin
中科院分区：
文献类型：
--
作者：
Long, Wu-Jian;Ye, Tao-Hua;Feng, Gan-Lin
钙浸出是硬化水泥复合材料中的一种降解过程，水泥孔隙溶液中的钙离子可以迁移到侵蚀性溶液中。采用电化学阻抗谱(EIS)和扫描电子显微镜(SEM)相结合的方法，对氧化石墨烯(GO)增强水泥基复合材料的钙浸出过程进行了有效的表征。探讨了GO对复合材料钙浸出的抑制机理。结果表明，添加GO的浸出样品奈奎斯特曲线的半圆直径减小幅度小于对照样品。浸出35d后，加入0、0.05、0.1、0.15和0.2wt.%GO的模型阻抗RCCP损失率分别为94.85%、84.07%、79.66%、75.34%和68.75%。因此，GO的加入能够吸附水泥孔隙溶液中的钙离子，改善水泥复合材料的微观结构，从而显著缓解水泥复合材料中钙的浸出。此外，利用阻抗RCCP对耦合淋滤深度和抗压强度损失进行了准确预测。
Calcium leaching is a degradation progress inside hardened cement composites, where Ca2+ ions in cement pore solution can migrate into the aggressive solution. In this work, calcium leaching of graphene oxide (GO) reinforced cement composites was effectively characterized by combined techniques of electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). Inhibiting mechanism of GO on calcium leaching of the composites was also examined. The obtained results show that the diameter of the semi-circle of the Nyquist curves of leached samples with GO addition decreased less than that of controlled samples. After leaching for 35 days, loss rate of model impedance RCCP of leached samples with 0, 0.05, 0.1, 0.15, and 0.2 wt.% GO addition was 94.85%, 84.07%, 79.66%, 75.34%, and 68.75%, respectively. Therefore, GO addition can significantly mitigate calcium leaching of cement composites, since it can absorb Ca2+ ions in cement pore solution, as well as improve the microstructure of the composites. In addition, coupling leaching depth and compressive strength loss were accurately predicted by using the impedance RCCP.