环糊精包合有机磷酸作为缓蚀剂的理论研究

采用分子模拟对三种有机磷酸(5-单磷酸腺苷(A)、羟基乙叉二磷酸(B)、2-磷酸基-1, 2, 4-三羧酸丁烷(C))及其与阳离子改性的β-环糊精(HPTEA-β-CD)形成的包合物作为缓蚀剂进行了理论研究,并通过失重法进行了实验验证.量子化学的计算结果表明,三种有机磷酸分子的反应活性主要集中在N、O、P等原子上,其中C分子的反应活性更强.同时采用分子动力学模拟HPTEA-β-CD包合A、B、C分子作为缓蚀剂在Fe(001)表面上的平衡吸附,结果表明C-HPTEA-β-CD的缓蚀效率最强.通过失重法分析,三种缓蚀剂对q²35碳钢均有良好的缓蚀性,其中C-HPTEA-β-CD的缓蚀效率最高,达到了91.50%,实验结果与理论计算的分析一致.

Theoretical Investigation on Cyclodextrin Inclusion Complexes with Organic Phosphoric Acid as Corrosion Inhibitor

The adsorption properties of amino methylene phosphonic acid (A), hydroxyethylenediphosphonic acid (B), sodium phosphonobutanetricarboxylic acid (C) and their inclusions with cationic modified betacyclodextrin (HPTEA-β-CD) for mild steel are evaluated by a combination of quantum chemistry and molecular dynamics simulations. The theoretical conclusions are experimentally verified by the weight loss method. The theoretical results indicate that reaction activity sites of A, B, and C are mainly concentrated at the N, O, P atoms, and the C molecule exhibited the highest reaction activity. Molecular dynamics method presents the equilibrium adsorption behavior of three HPTEA-β-CD inclusion complexes with molecules A, B, and C on an Fe(001) surface, and molecular C-HPTEA-β-CD exhibits the best inhibition performance, according to the adsorption energy. Experimental results of the weight loss show that the three inhibitors exert an excellent corrosion inhibition performance to q²35 steel, and C-HPTEA-β-CD exhibits the highest corrosion efficiency of 91.50%, which is in good accordance with theoretical results.