Gemini表面活性剂与卤离子对钢在磷酸介质中缓蚀协同效应

通过失重法与极化曲线法考察了季铵盐型Gemini表面活性剂1,3-双(十二烷基二甲基溴化铵)丙烷(简写为12-3-12)及其与卤离子复合体系对冷轧钢在1 mol.L-1磷酸溶液中的缓蚀协同效应.实验结果表明,在一定浓度氯离子或溴离子的存在下,浓度很低的Gemini表面活性剂12-3-12(1×10-4mol.L-1)就可以对冷轧钢在磷酸介质中起到很好的缓蚀效果;通过在Gemini表面活性剂12-3-12溶液中加入一定浓度的Cl-或Br-构筑复合的缓蚀体系,利用表面活性剂与卤离子之间显著的缓蚀协同效应,大大降低了Gemini表面活性剂在缓蚀体系中的用量,极大地降低了Gemini表面活性剂作为酸介质中钢的缓蚀剂的综合使用成本;对酸介质中Gemini表面活性剂复合缓蚀体系在金属表面的吸附机理进行了探讨,并通过Langmuir吸附理论和相关公式得到了相关热力学参数.

Synergistic effect between gemini surfactant and halide ions for the corrosion inhibition of steel in phosphoric acid

Synergistic effect of chloride and bromide ions on corrosion inhibition of steel in 1mol·L-1 phosphoric acid solution by quaternary ammonium salt type gemini surfactants,1,3-propane-bis(dimethyl dodecylammonium bromide)(12-3-12),was investigated using weight loss and Tafel polarization curve methods.The results revealed significant synergistic effect between gemini 12-3-12 and halide ions for the corrosion protection of cold rolled steel in phosphoric acid,and that the novel composite inhibitor system containing quaternary ammonium salt type gemini surfactant and halide ions was efficient and low-cost for steel corrosion inhibition in phosphoric acid medium,even when concentration of 12-3-12 was as low as 1×10-4mol·L-1.By fitting the obtained experimental data with Langmuir adsorption model,some thermodynamic parameters such as adsorption free energy were obtained.