Preparation and characterization of nanocontainers of corrosion inhibitor based on layered double hydroxides

Nanostructured zinc aluminum and magnesium aluminum layered double hydroxide (ZnAl-LDH and MgAl-LDH) intercalated with corrosion inhibitor 2-benzothiazolylthio-succinic acid (BTSA) were prepared using co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, scanning electronic microscopy and transmission electronic microscopy. BTSA release from ZnAl(BTSA)-LDH and MgAl(BTSA)-LDH in 3 wt.% NaCl and 3 wt.% Na2SO4 solution was investigated with UV-vis spectroscopy. and inhibitive action of ZnAl(BTSA)-LDH and MgAl(BTSA)-LDH on carbon steel was examined by electrochemical methods. It was shown that the formula of synthesized ZnAl(BTSA)-LDH and MgAl(BTSA)-LDH is [Zn2.4Al(OH)(6.8)](BTSA)(0.43)(NO3)(0.14)center dot 4H(2)O and [Mg2.1Al(OH)(5.96)](BTSA)(0.62)center dot 1.5H(2)O, respectively. The BTSA release was dependent on the anion type in electrolyte and the BTSA release in the presence of SO42- anion was higher than that in the presence of Cl- anion. The polarization curves obtained on the carbon steel sample showed that the ZnAl(BTSA)-LDH and MgAl(BTSA)-LDH are anodic inhibitors. Inhibition efficiency is higher with ZnAl(BTSA)-LDH, at the concentration of 3 g/l, achieving approximately 97% and 88% for ZnAl(BTSA)-LDH and MgAl(BTSA)-LDH, respectively. (C) 2012 Elsevier B.V. All rights reserved.