Pascoal Caio Victor Pereira, Da Silva Lucas Renan Rocha, Florez Mauro Andres Cerra, Cavalcante Thiago Roberto Felisardo, Avila Julian Arnaldo, Salomão Francisco Carlos Carneiro Soares, Barros Eduardo Bedê, Avelino Francisco, Lomonaco Diego, Pinheiro Regiane Silva, de Sant'Ana Hosiberto, Rezayat Mohammad, Mateo Antonio, Fargas Gemma, Araújo Walney Silva
Department of Metallurgical and Materials Engineering, Federal University of Ceará (UFC), Fortaleza 60440-900, CE, Brazil.
Department of Materials Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), São Carlos 13566-590, SP, Brazil.
Molecules. 2025 Feb 24;30(5):1033. doi: 10.3390/molecules30051033.
The inhibitory performance of three distinct protic ionic liquids (PILs), namely, 2-hydroxyethyl ammonium formate (PIL 01), 2-hydroxyethyl ammonium propionate (PIL 02), and 2-hydroxyethyl ammonium pentanoate (PIL 03), was evaluated to determine their suitability as eco-friendly corrosion inhibitors for carbon steel (ASTM A36) in a 3.5 wt. % NaCl aerated neutral electrolyte solution. Standard corrosion inhibitor assessment methods, including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), weight loss measurements, and microscopic techniques (SEM and optical microscopy), were employed to examine the steel surface and corrosion rate. There is a general agreement that the inhibition efficacy is directly associated with the adsorption capacity of substances on the surface of an investigated material, normally stainless or carbon steel. The standard free energies of adsorption were approximately -22 kJ mol, indicating a physical adsorption type of interaction between ionic liquids and the electrode surface. The adsorption behavior of protic ionic liquids on an A36 steel surface conforms to a Langmuir-type isotherm. In conclusion, PIL 01 demonstrated an inhibition efficiency exceeding 80%, while PILs 02 and 03 exhibited efficacies in the 50-60% range. The inhibition efficiency was observed to be proportional to the inhibitor's concentration. These results suggest that PIL 01, PIL 02, and PIL 03 exhibit significant corrosion inhibition properties.
评估了三种不同的质子离子液体（PILs），即甲酸2-羟乙基铵（PIL 01）、丙酸2-羟乙基铵（PIL 02）和戊酸2-羟乙基铵（PIL 03）的缓蚀性能，以确定它们作为3.5 wt.% NaCl充气中性电解质溶液中碳钢（ASTM A36）的环保型缓蚀剂的适用性。采用了标准的缓蚀剂评估方法，包括电化学阻抗谱（EIS）、动电位极化（PDP）、失重测量和微观技术（SEM和光学显微镜）来检查钢表面和腐蚀速率。人们普遍认为，缓蚀效果与物质在被研究材料（通常是不锈钢或碳钢）表面的吸附能力直接相关。吸附的标准自由能约为-22 kJ/mol，表明离子液体与电极表面之间存在物理吸附类型的相互作用。质子离子液体在A36钢表面的吸附行为符合朗缪尔型等温线。总之，PIL 01的缓蚀效率超过80%，而PIL 02和PIL 03的缓蚀效率在50%-60%范围内。观察到缓蚀效率与缓蚀剂浓度成正比。这些结果表明，PIL 01、PIL 02和PIL 03具有显著的缓蚀性能。
