Bonfil David, Veleva Lucien, Ramos-López Diana Rubi, González-Gómez William Santiago, Bolio-López Gloria Ivette
Applied Physics Department, Center for Research and Advances Study (CINVESTAV), Campus Merida, Merida, Yucatan 97310, Mexico.
Popular University of Chontalpa, Cardenas-Huimanguillo Highway Km. 2.0, Cardenas 86500, Mexico.
ACS Omega. 2024 Nov 27;9(49):48536-48545. doi: 10.1021/acsomega.4c07363. eCollection 2024 Dec 10.
Natural nutshell extract was obtained by mechanical compression. The extract was combined with ethanol and a nonionic surfactant, and it was labeled as EES. The EES inhibitor effect on S135 carbon steel, exposed to a simulated marine-coastal environment (SME), was deduced by mass loss measurement, adsorption isotherm, electrochemical measurements, and surface analysis. The Langmuir adsorption isotherm suggested that a monolayer of the extract was attached by physical-chemical interaction with the steel surface. The increase in the protective efficiency of the adsorbed EES inhibitor was ascribed to the gain of the surface coverage as a function of the inhibitor concentration. It was considered an antioxidant activity of the inhibitor, attributed mostly to the Fe-ion capture by anacardic acid and the posterior ion chelation. This fact was collaborated by the negative zeta potential of the nutshell extract, added to the SME. Electrochemical impedance spectroscopy (EIS) diagrams revealed that the steel polarization resistance ( ) increased as a function of the inhibitor concentration, while the thickness () of the Fe-oxide layer was reduced to ≈0.50 nm.
天然坚果壳提取物通过机械压缩获得。将该提取物与乙醇和一种非离子表面活性剂混合，并标记为EES。通过质量损失测量、吸附等温线、电化学测量和表面分析，推断EES对暴露于模拟海洋沿海环境（SME）中的S135碳钢的抑制作用。朗缪尔吸附等温线表明，提取物的单分子层通过与钢表面的物理化学相互作用附着。吸附的EES抑制剂保护效率的提高归因于表面覆盖率随抑制剂浓度的增加。它被认为是抑制剂的抗氧化活性，主要归因于腰果酚对铁离子的捕获以及随后的离子螯合。添加到SME中的坚果壳提取物的负zeta电位证实了这一事实。电化学阻抗谱（EIS）图显示，钢的极化电阻（ ）随抑制剂浓度的增加而增加，而氧化铁层的厚度（ ）减小至约0.50 nm。
