空心莲子草提取物对钢在硫酸溶液中的缓蚀性能  

Inhibition action of alternanthera philoxeroides extract on steel in sulfuric acid solution

作　　者：张富 李向红 ZHANG Fu;LI Xiang-hong(College of Chemical Engineering,Southwest Forestry University,Kunming 650224,China;Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学化学工程学院,云南昆明650224 [2]西南林业大学西南地区林业生物质资源高效利用国家林业和草原局重点实验室,云南昆明650224

出　　处：《化学研究与应用》2021年第8期1472-1479,共8页Chemical Research and Application

基　　金：云南省基础研究计划“杰出青年项目”(202001AV070008)资助;云南省万人计划“青年拔尖人才”专项(51900109)资助。

摘　　要：以空心莲子草(Alternanthera philoxeroides)为原料,采用40%(体积分数)乙醇水溶液为提取溶剂进行回流提取制得空心莲子草提取物(APE)。采用失重法、电化学法、扫描电子显微镜(SEM)及原子力显微镜(AFM)研究了APE在0.5 mol·L^(-1) H2SO4溶液中对冷轧钢的缓蚀性能及作用机理。结果表明,APE对冷轧钢在H2SO4溶液中具有较好的缓蚀性能,缓蚀率随APE浓度增加而增大,50℃时100 mg·L^(-1) APE的缓蚀率为84.7%;APE在钢表面的吸附模型符合Langmuir吸附等温式,且标准吸附Gibbs自由能为-29 kJ·mol^(-1)~-26 kJ·mol^(-1);动电位极化曲线表明APE属于抑制阴极为主的混合抑制型缓蚀剂;Nyquist图谱在高频区呈弥散容抗弧,而在低频区有小段感抗弧,添加APE后电荷转移电阻显著增大,SEM和AFM表征表明APE在冷轧钢表面形成吸附膜并起到缓蚀作用。Alternanthera philoxeroides was used as the raw material.Alternanthera philoxeroides extract(APE)was prepared using reflux method with 40%(volume fraction)ethanol water solution.The inhibitive action and mechanism of WGHE on cold rolled steel(CRS)in 0.5 mol·L^(-1) H 2SO 4 solution were studied by weight loss,electrochemical technique,scanning electron microscope(SEM)and atomic force microscope(AFM)methods.The results show that APE exhibits good inhibitive ability,and inhibition efficiency increases with the increase of concentration.The inhibition efficiency of 100 mg·L^(-1) APE reached as high as 84.7%.The adsorption of APE on CRS surface obeys Langmuir isotherm,and the standard adsorption energy is from-29 kJ·mol^(-1) to-26 kJ·mol^(-1) .Potentiodynamic polarization curves indicates that APE acts as a mixed-type corrosion inhibitor while mainly inhibits the cathodic reaction.Nyquist spectra appears a depressed capacitive loop at high frequencies followed by a small inductive section at low frequencies.The charge transfer resistance is significantly increased with the addition of APE.SEM and AFM clearly confirm that APE can form an adsorption film on steel surface that exerts inhibitive performance.

关 键 词：空心莲子草提取物 缓蚀 冷轧钢 硫酸 吸附 

分 类 号：O614.8[理学—无机化学]