School of Material and Chemical Engineering, Tongren University, Tongren 554300, China.
School of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing 408100, China.
J Colloid Interface Sci. 2020 Jun 15;570:116-124. doi: 10.1016/j.jcis.2020.03.001. Epub 2020 Mar 2.
3,3-Dithiodipropionic acid (DDA) as a potential corrosion inhibitor for Q235 steel in 0.5 M HSO solution was examined. A variety of research approaches including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), atomic force microscopy (AFM), and computational techniques were employed. The toxicity and solubility of DAA were reasonably assessed. Its inhibition efficiency can reach approximately 93% when the optimal concentration is 5 mM. The results of PDP curves manifest that DDA is a mixed type corrosion inhibitor. EIS data indicate that the charge transfer resistance increases with increasing concentration of DDA. Gibbs free energy obtained from the Langmuir isotherm model suggests that DDA molecules hinder the acid attack mainly by chemisorption. Surface topography analysis strongly confirmed the electrochemical findings. Moreover, the simulation results based on density functional theory (DFT) calculation and molecular dynamics (MD) simulations supported the successful interfacial adsorption of DDA on Fe(1 1 0) surface.
3,3-二硫代二丙酸（DDA）可用作 Q235 钢在 0.5 M HSO 溶液中的潜在缓蚀剂。采用电化学阻抗谱（EIS）、动电位极化（PDP）、扫描电子显微镜（SEM）、原子力显微镜（AFM）和计算技术等多种研究方法对其进行了研究。合理评估了 DAA 的毒性和溶解度。当最佳浓度为 5 mM 时，其抑制效率可达到约 93%。PDP 曲线的结果表明，DDA 是一种混合型缓蚀剂。EIS 数据表明，随着 DDA 浓度的增加，电荷转移电阻增大。从 Langmuir 等温模型获得的吉布斯自由能表明，DDA 分子主要通过化学吸附阻碍酸的侵蚀。表面形貌分析有力地证实了电化学研究结果。此外，基于密度泛函理论（DFT）计算和分子动力学（MD）模拟的模拟结果支持 DDA 在 Fe（110）表面上的成功界面吸附。
