LDH型MoO42-缓蚀剂的合成及防腐研究

Synthesis and anticorrosive properties of molybdate inhibitor base on intercalated layered double hydroxide (LDH)

摘要:

采用共沉淀法制备了储存缓蚀剂MoO42-的镁铝水滑石(LDH)纳米容器(MoO42—LDH)，利用XRD和Raman光谱对样品进行表征。通过缓释实验，讨论了LDH型纳米容器对缓蚀剂的释放能力以及缓蚀剂的缓蚀机理。SEM-EDS、ICP、N2吸附脱附和极化曲线测试结果表明合成的LDH型MoO42-缓蚀剂具有很好的离子交换和吸附Cl-的性能，释放出MoO42-缓蚀剂进入电解液，24h内对镁合金的腐蚀电流保持在9.129A穋m-2，展示了良好的缓蚀防腐性能。添加20%MoO42—LDH颜料的环氧涂层在3.5%NaCl溶液中的EIS测试体现出较好的耐蚀作用。

Abstract:

Mg-Al layered double hydroxide (LDH) as a container, loaded with molybdate anions,were synthesized via the coprecipitation method. The resulting compounds were characterized by X-ray diffraction (XRD) and Raman spectra, respectively. The properties of the release of inhibitor and the inhibition mechanism were observed and analyzed by slow-release experiment. The SEM-EDS、ICP and N2 adsorption-desorption measurements demonstrated the excellent anion-exchange and adsorption capabilities for chloride ion . Polarization curves measurements showed that the filtrate as electrolyte exhibited a lower corrosion current density value due to the presence of MoO42-.The result was demonstrated that the released inhibitor can provide adequate corrosion protection, maintaining a corrosion current density at approximately 9.129A穋m-2 for magnesium alloy within 24h. The coatings containing 20% MoO42—LDH pigment keep excellent corrosion resistance by electrochemical impedance spectroscopy (EIS) during immersion in 3.5% NaCl solution.