Ethyl-bis(octadecyl dipolyoxyethylene ammonium chloride) (E-BODAC) was a novel quaternary Gemini surfactant and was first found and identified as an excellent inhibitor with excellent surface activity and suitability. The ethoxy group enhances its hydrophilicity, and facilitates a dense adsorption film on metal surface. The inhibitive action and mechanism of E-BODAC on cold rolled steel (CRS) in HCl and H₂SO₄ solutions was studied in detail by theoretical and experimental methods. The surface activity and degree of polymerization of the surfactant are tightly related to the anti-corrosion properties. HCl has a lower critical micelle concentration (CMC) than H₂SO₄ solutions. The hydrophilic group in E-BODAC is the preferred site for donating and accepting electrons, with chemical interactions occurring among O, C, and Fe. The addition of E-BODAC obeys Langmuir isotherm, which can drastically reduce the diffusion of H₃O⁺, Cl⁻/SO₄²⁻. E-BODAC has superior corrosion inhibition performance and lower dosage, and the inhibition efficiency for CRS reaches 92.9% in 1.0 M HCl with only 10 mg L⁻¹ of E-BODAC and 91.5% in 0.50 M H₂SO₄. The inhibition is through physical and chemical adsorption to form a protective film that covers the reaction site, blocking the corrosion reaction. CLSM, SEM, AFM, XPS, and time-of-flight secondary ion mass spectrometer (TOF-SIMS) provide evidence of the adsorption of E-BODAC, efficiently slowing down the corrosion of CRS surface. E-BODAC always shows higher efficiency in HCl than in H₂SO₄, which is attributed to the re-dissolution of the adsorbed film in the H₂SO₄ solution. Besides, SO₄²⁻ ions are larger and migrate more slowly than Cl⁻ ions, resulting in weak adsorption on the metal surface. The assessment of E-BODAC's suitability and durability in different corrosive environments provides the opportunity to determine its optimum conditions and applicability to maximize its corrosion inhibition effect.

中文翻译：

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新型季铵 Gemini 表面活性剂作为 HCl 和 H2SO4 溶液中钢腐蚀的高效抑制剂


乙基双（十八烷基二聚氧乙烯氯化铵）（E-BODAC）是一种新型季铵盐双子表面活性剂，首次被发现并被鉴定为具有优异表面活性和适用性的优良抑制剂。乙氧基增强了其亲水性，并有助于在金属表面形成致密的吸附膜。通过理论和实验方法详细研究了 E-BODAC 对 HCl 和 H₂SO₄ 溶液中冷轧钢 （CRS） 的抑制作用和机理。表面活性剂的表面活性和聚合度与防腐性能密切相关。HCl 的临界胶束浓度 （CMC） 低于 H₂SO₄ 溶液。E-BODAC 中的亲水基团是供体和接受电子的首选位点，O、C 和 Fe 之间发生化学相互作用。E-BODAC 的添加遵循 Langmuir 等温线，它可以大大减少 H₃O⁺， Cl^-/SO₄^2- 的扩散。E-BODAC 具有优异的缓蚀性能和较低的用量，仅含 10 mg ^L-1 的 E-BODAC 和 91.5% 的 0.50 M H₂SO₄，在 1.0 M HCl 中对 CRS 的抑制效率达到 92.9%。抑制是通过物理和化学吸附形成覆盖反应位点的保护膜，阻断腐蚀反应。CLSM、SEM、AFM、XPS 和飞行时间二次离子质谱仪 （TOF-SIMS） 提供了 E-BODAC 吸附的证据，有效减缓了 CRS 表面的腐蚀。 E-BODAC 在 HCl 中的效率始终高于 H₂SO₄，这归因于吸附膜在 H₂SO₄ 溶液中的重新溶解。此外，SO₄²⁻ 离子比 Cl⁻ 离子更大，迁移速度更慢，导致在金属表面的吸附较弱。对 E-BODAC 在不同腐蚀环境中的适用性和耐久性的评估提供了确定其最佳条件和适用性的机会，以最大限度地发挥其腐蚀抑制效果。