Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (11): 2092-2100.doi: 10.3866/PKU.WHXB201408282

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Effect of Doping with Zn-Al-[V10O28]6- Layered Double Hydroxide on the Properties of Hybrid Sol-Gel Coatings on the LY12 Aluminum Surface

LI Song-Mei, YIN Xiao-Lin, LIU Jian-Hua, ZHANG You, XUE Bing   

  1. College of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, P. R. China
  • Received:2014-06-19 Revised:2014-08-28 Published:2014-10-30
  • Contact: LI Song-Mei E-mail:songmei_li@buaa.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51271012).

Abstract:

Zn-Al-[V10O28]6- layered double hydroxide (LDH-V) as a type of corrosion inhibitor was prepared with the co-precipitation method using one solution containing zinc and aluminum nitrates precursors and a second solution containing Na3VO4, where the decavanadate anion is speciated at pH 4.5. The hybrid solgel solution was prepared from 3-glycydoxypropyltrimethoxysilane (GPTMS) as the organic precursor sol and zirconium n-propoxide (TPOZ) as the inorganic precursor sol. The doped coatings were obtained by dip coating the way that the samples were immersed into solutions with different LDH-V concentrations (0.0, 0.25×10-3, 0.75×10-3, 1.5×10-3, 3.0×10-3 mol·L-1). The morphology and corrosion resistance of the solgel coating doped with different LDH-V concentrations were studied. The sol-gel coatings were investigated by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The salt spray test was used to evaluate the corrosion resistance of the different coatings. The corrosion behavior of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) during immersion in 0.05 mol·L-1 NaCl solution. The results showed that LDH-V not only improves the corrosion resistance of the coating, but also provides a function for self-healing of broken coatings. However, when the LDH-V doping concentration was high, it destroyed the integrity of the coatings and decreased the corrosion resistance of the coatings. The best LDH-V doping concentration was 1.5×10-3 mol·L-1.

Key words: Sol-gel coating, Zn-Al layered double hydroxide, [V10O28]6-, Corrosion protection, Electrochemical impedance spectroscopy

MSC2000: 

  • O646