Onukwuli O D, Nnanwube I A, Ochili F O, Obibuenyi J I
Department of Chemical Engineering, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Anambra State, Nigeria.
Department of Chemical Engineering, Madonna University, Akpugo Campus, 402105, Akpugo, Enugu State, Nigeria.
Heliyon. 2024 Dec 6;10(24):e40994. doi: 10.1016/j.heliyon.2024.e40994. eCollection 2024 Dec 30.
The present study examined the corrosion protection of aluminium in 1M HCl by deploying expired danacid, with techniques such as gravimetric, electrochemical, and density functional theory (DFT). Inhibitor characterization was executed with Fourier transform infrared (FTIR) spectroscopy and gas chromatography mass spectrometry (GC-MS), which was supplemented by optimization of parameters with response surface methodology. The results of gravimetric study indicates that the inhibition efficiency (IE) rose with rise in danacid concentration and reduced with rise in temperature. FTIR results shows the presence of heteroatoms in the inhibitor while further analysis by GC-MS showed the presence of heteroatom-carrying compounds such as menthyl acetate, eicosyl vinyl ester, carbonic acid, dotriacontane, n-hexadecanoic acid, among others. The activation energy value obtained from this work suggest that the inhibitor molecule's adsorption on the surface of aluminium follows physical adsorption mechanism. Potentiodynamic polarization (PDP) results portrays the inhibitor as a mixed-type while the results of electrochemical impedance spectroscopy (EIS) tests gave an inhibition efficiency of 95.05 %. RSM results show optimum inhibition efficiency of 93.57 % while artificial neural network (ANN) gave improved predicted values. The DFT results further show that the danacid molecules could effectively inhibit alumina corrosion in aggressive media. Hence, danacid proved to be a viable inhibitor for aluminium corrosion.
本研究通过使用过期丹那酸，采用重量法、电化学法和密度泛函理论（DFT）等技术，研究了铝在1M盐酸中的腐蚀防护。用傅里叶变换红外（FTIR）光谱和气相色谱-质谱联用（GC-MS）对缓蚀剂进行了表征，并通过响应面法对参数进行了优化。重量法研究结果表明，缓蚀效率（IE）随丹那酸浓度的增加而升高，随温度的升高而降低。FTIR结果表明缓蚀剂中存在杂原子，而GC-MS的进一步分析表明存在含杂原子的化合物，如乙酸薄荷酯、二十烷基乙烯酯、碳酸、三十二烷、正十六烷酸等。本研究得到的活化能值表明，缓蚀剂分子在铝表面的吸附遵循物理吸附机制。动电位极化（PDP）结果表明缓蚀剂为混合型，而电化学阻抗谱（EIS）测试结果的缓蚀效率为95.05%。响应面法结果显示最佳缓蚀效率为93.57%，而人工神经网络（ANN）给出了改进的预测值。DFT结果进一步表明，丹那酸分子可以有效抑制活性介质中氧化铝的腐蚀。因此，丹那酸被证明是一种可行的铝腐蚀缓蚀剂。
