Kim Jae-Yeon, Shin Inji, Byeon Jai-Won
Program of Material Science and Engineering, Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology, Seoul 01811, Korea.
Department of Mining and Geological Engineering, University of Arizona, Tucson, AZ 85721, USA.
Materials (Basel). 2021 Sep 2;14(17):5016. doi: 10.3390/ma14175016.
Tea tree extract, containing antioxidant constituents α-terpineol, terpinen-4-ol, and α-terpinene, has a wide range of applications in the cosmetic, food, and pharmaceutical industries. In this study, tea tree extract showed an anticorrosive effect under 1 M HCl solution on mild steel (MS) and 304 stainless steel (STS). Uniform corrosion for MS and pitting corrosion for STS at 298 K were retarded, with inhibition efficiencies of 77% and 86%, respectively. The inhibition of uniform and pitting corrosion was confirmed by scanning electron microscopy and laser scanning confocal microscopy in terms of surface roughness and pitting morphologies. The most effective constituent contributing to the inhibitory performance of tea tree extract was revealed to be α-terpineol, with an inhibition efficiency of 83%. The adsorption of tea tree extract was confirmed by surface characterization analysis using Fourier transform infrared spectroscopy, Raman spectroscopy, and Electrochemical impedance spectroscopy. Interestingly, G- and D-peaks of Raman spectra were detected from the inhibited steels, and this finding is the first example in the corrosion inhibition field. The anticorrosion mechanism can be explained by the formation of organic-Fe complexes on the corroded steel surface via electron donor and acceptor interactions in the presence of an oxygen atom of the hydroxyl group or ether of organic inhibitors.
茶树提取物含有抗氧化成分α-松油醇、萜品-4-醇和α-萜品烯，在化妆品、食品和制药行业有广泛应用。在本研究中，茶树提取物在1 M盐酸溶液中对低碳钢（MS）和304不锈钢（STS）显示出防腐效果。在298 K时，低碳钢的均匀腐蚀和304不锈钢的点蚀均受到抑制，抑制效率分别为77%和86%。通过扫描电子显微镜和激光扫描共聚焦显微镜从表面粗糙度和点蚀形态方面证实了对均匀腐蚀和点蚀的抑制作用。结果表明，对茶树提取物抑制性能贡献最大的成分是α-松油醇，抑制效率为83%。通过傅里叶变换红外光谱、拉曼光谱和电化学阻抗谱进行表面表征分析，证实了茶树提取物的吸附。有趣的是，在被抑制的钢上检测到了拉曼光谱的G峰和D峰，这一发现是腐蚀抑制领域的首例。防腐机理可以解释为在有机抑制剂的羟基或醚的氧原子存在下，通过电子供体和受体相互作用在腐蚀的钢表面形成有机-Fe络合物。
