Three gemini cationic surfactants as biodegradable corrosion inhibitors for carbon steel in HCl solution
作者:Salah M. Tawfik、Ali A. Abd-Elaal、Ismail Aiad
DOI:10.1007/s11164-015-2076-4
日期:2016.2
Three gemini cationic surfactants with different hydrophobic spacer chain lengths were synthesized and characterized. The inhibition effect of N,N′-bis(2-hydroxyethyl)-N,N′-dimethyl-N,N′-bis(2-(tetradecanoyloxy)ethyl)ethane-1,2-diaminium bromide (G-2); N,N′-bis(2-hydroxyethyl)-N,N′-dimethyl-N,N′-bis(2-(tetradecanoyloxy)ethyl) hexane-1,6-diaminium bromide (G-6); and N,N′-bis(2-hydroxyethyl)-N,N′-dimethyl-N,N′-bis (2-(tetradecanoyloxy) ethyl) dodecane-1,12-diaminium bromide (G-12) on the corrosion of carbon steel in 1.0 M HCl solution at 25–60 °C was studied by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy. The results show that the synthesized inhibitors are effective inhibitors even at very low concentration, and the adsorption on the carbon steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization curves reveal that the synthesized inhibitors behave as a mixed-type inhibitor. Adsorption of used inhibitors led to a reduction in the double layer capacitance and an increase in the charge transfer resistance. Thermodynamic parameters have been obtained by adsorption theory. Surface activity and corrosion inhibition relationship were discussed. The biodegradability of the synthesized surfactants showed their readily biodegradation in the open environment and were considered as environmentally friendly corrosion inhibitors.
合成了三种具有不同疏水间隔链长度的双子阳离子表面活性剂,并对其进行了表征。通过失重法、电位动力学极化和电化学阻抗谱研究了 N,N′-双(2-羟乙基)-N,N′-二甲基-N,N′-双(2-(十四烷酰氧基)乙基)乙烷-1,2-二氨基溴化物 (G-2); N,N′-双(2-羟乙基)-N,N′-二甲基-N,N′-双(2-(十四烷酰氧基)乙基)己烷-1,6-二氨基溴化物 (G-6); 和 N,N′-双(2-羟乙基)-N,N′-二甲基-N,N′-双(2-(十四烷酰氧基)乙基)十二烷-1,12-二氨基溴化物 (G-12) 对 1.0 M 盐酸溶液中 25–60 °C 下碳钢腐蚀的抑制作用。结果表明,合成的抑制剂即使在极低浓度下也是有效的抑制剂,并且在碳钢表面的吸附服从 Langmuir 吸附等温线。电位动力学极化曲线显示合成的抑制剂表现为混合型抑制剂。所用抑制剂的吸附导致双层电容降低和电荷转移电阻增加。通过吸附理论获得了热力学参数。讨论了表面活性和腐蚀抑制之间的关系。合成的表面活性剂的生物降解性表明它们在开放环境中容易生物降解,并被认为是环境友好的腐蚀抑制剂。