咖啡果皮提取物对钢在三氯乙酸溶液中的缓蚀性能  

Inhibitory Action of Coffee Skin Extract on Corrosion of Steel in Trichloroacetic Acid Solution

作　　者：穆显菊 李向红[1,2] 雷然[1,2] 邓书端[1,2] MU Xianju;LI Xianghong;LEI Ran;DENG Shuduan(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;College of Materials and Chemical Engineering,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]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,昆明650224 [2]西南林业大学材料与化学工程学院,昆明650224

出　　处：《中国腐蚀与防护学报》2024年第6期1465-1475,共11页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(52161016);云南省农业基础研究联合专项重点项目(202101BD070001-017);云南省万人计划青年拔尖人才专项(51900109);云南省基础研究计划重点项目(202301AS070043);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开放基金项目(2022-KF08)。

摘　　要：采用失重法、电化学法、红外光谱(FTIR)、扫描电子显微镜(SEM)、接触角、表面张力等测试研究了农林废弃物咖啡果皮提取物(CSE)在0.10 mol·L^(-1)三氯乙酸(Cl_3CCOOH)中的缓蚀性能。结果表明,500 mg·L^(-1)CSE在20℃时缓蚀率高达93.7%;20和30℃下CSE在钢表面的吸附规律遵循Langmuir吸附等温式,而40和50℃下则服从Freundlich吸附等温式,标准吸附Gibbs自由能(ΔG~0)在-30~-41 kJ·mol^(-1)范围,CSE在钢表面的吸附类型为以化学吸附为主的混合吸附。CSE属于阴极抑制型缓蚀剂。添加CSE使电荷转移电阻增大,而界面双电层电容值下降。添加CSE的缓蚀钢表面的SEM微观形貌腐蚀程度和粗糙程度显著下降,但疏水性增强。FTIR表明CSE中含有大量O原子和芳香环等极性基团。随着CSE的添加,缓蚀溶液体系的表面张力逐渐降低,溶液电导率增加,钢腐蚀浸泡后,溶液表面张力较浸泡前有所增加,而溶液电导率较浸泡前有所降低。The corrosion inhibition performance of the agricultural and forestry waste of coffee skin extract(CSE)in 0.10 mol·L^(-1)trichloroacetic acid(Cl_3CCOOH)for plate of a cold rolled steel(CRS)was investigated by mass loss method,electrochemical tests,infrared spectroscopy(FTIR),scanning electron microscope(SEM),contact angle and surface tension measurements.The results show that the inhibition efficiency of 500 mg·L^(-1)CSE can reach as high as 93.7%at 20℃.The adsorption of CSE on CRS follows Langmuir adsorption isotherm at 20℃and 30℃,while follows Freundlich adsorption isotherm at 40℃and 50℃.The standard Gibbs free energy(ΔG~0)is in the range of-30~-41 kJ·mol^(-1).The adsorption type of CSE on CRS is the mixed adsorption mainly by chemisorption.CSE is a cathodic-type inhibitor.With the presence of CSE in 0.10 mol·L^(-1)trichloroacetic acid solution the charge transfer r reactance increases,while the interface double layer capacitance reduces for the steel surface.As a subsequence,the corrosion degree and roughness of the steel surface decrease significantly,but its hydrophobicity is enhanced.FTIR confirms that CSE contains a large number of polar groups such as O atoms and aromatic rings.As the CSE concentration increases,the surface tension of the corrosive Cl_3CCOOH solution gradually decreased,and the conductivity of the solution increased.After the immersion of the test steel in the solution,the surface tension of the solution is increased,while its conductivity decreased.

关 键 词：咖啡果皮提取物 三氯乙酸 钢 缓蚀 吸附 

分 类 号：TG174[金属学及工艺—金属表面处理]