ABSTRACT

Layered double hydroxides (LDHs) can serve as corrosion inhibitor reservoirs. In the present work, hydrotalcite-like LDHs were synthesized and employed as host matrixes for the release of phosphate. The morphological and structural properties of the as-prepared LDH-PO₄ were characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The PO₄^3- adsorption uptake was successfully confirmed by the XRD results. The corrosion resistance of the coating with LDH-PO₄ was investigated by electrochemical impedance spectroscopy (EIS), which was approximately 1 order of magnitude higher than that of the blank coating after immersion for 168 h. Results of the scanning Kelvin probe technique revealed that the potential of LDH-PO4 coating was higher and smoother than that of the blank coating after exposure to 0.5 M NaCl solution. This effect is attributed to the release of PO₄³⁻ that forms a phosphate protective film in the scratched region.

摘要

层状双氢氧化物 (LDH) 可用作缓蚀剂储层。在目前的工作中，合成了类水滑石的 LDH，并将其用作释放磷酸盐的主体基质。通过扫描电子显微镜(SEM)、X射线衍射(XRD)和傅里叶变换红外光谱(FT-IR)对所制备的LDH-PO _{4的形态和结构特性进行了表征。}XRD结果成功地证实了PO ₄ ^{3-吸附吸收。}_{LDH-PO 4}涂层的耐腐蚀性能通过电化学阻抗谱 (EIS) 进行了研究，在浸泡 168 小时后，其比空白涂层高约 1 个数量级。扫描开尔文探针技术的结果表明，暴露于 0.5 M NaCl 溶液后，LDH-PO4 涂层的电位比空白涂层的电位更高且更光滑。这种效果归因于PO ₄ ^3-的释放，在划痕区域形成磷酸盐保护膜。