摘要
目的提高Q235碳钢的耐腐蚀性能。方法在Q235表面先提拉聚二甲基硅氧烷(PDMS),预固化后再次提拉含疏水气相二氧化硅的PDMS分散液,完全固化后在Q235表面构建一个SiO_(2)/PDMS超疏水涂层。通过扫描电镜、激光共聚焦显微镜、能谱、接触角、砂纸磨损、划格试验对涂层的形貌、结构和表面性质进行分析;采用电化学工作站对涂层的耐腐蚀性和耐久性进行评价。结果SiO_(2)纳米粒子被镶嵌在PDMS中,在Q235表面形成了一种微纳粗糙结构,平均粗糙度为2.2μm;涂层表面能仅为5.6 mJ/m^(2),接触角为152.6°;涂层机械稳定性和结合力优异,砂纸磨损15个周期及划格试验30个周期后,仍保持超疏水。电化学研究表明,在Q235表面引入SiO_(2)/PDMS后,阻抗提升了2个数量级,电容降低了6个数量级;腐蚀电位正向移动了0.4192 V,腐蚀电流密度降低了3个数量级;涂层对Q235的防腐效率高达99.8%,呈现出优异的耐腐蚀性。在腐蚀液中浸泡一周后,SiO_(2)/PDMS涂层仍保持超疏水和优异的耐腐蚀性,表明涂层耐久性良好。结论以PDMS为疏水层,纳米SiO_(2)为填料构筑粗糙表面,通过条件控制实现防腐底层和超疏水表层间的界面融合,从而引入稳定的SiO_(2)/PDMS超疏水涂层,提高了Q235的耐腐蚀性和耐久性。本研究为在金属表面构筑稳定的超疏水涂层提供了一种方法,有望拓展金属在恶劣环境中的应用。
Metal corrosion has brought huge losses to human society,so it is of great significance to study the corrosion and protection of materials.To improve the corrosion resistance of Q235 carbon steel,the work aims to prepare the SiO_(2)/PDMS super-hydrophobic coating on the surface of Q235,and discuss the corrosion resistance and mechanism of the composite coating.In this study,Q235 with a diameter of 13.5 mm and a thickness of 2.0 mm was selected as the metal substrate,and was ultrasonically cleaned by acetone,ethanol and deionized water respectively.Then,the pretreated Q235 was immersed in polydimethylsiloxane(PDMS)dispersion and hydrophobic vapor silica nanoparticles/PDMS dispersion successively,and was pulled at a speed of 1 mm/min to introduce SiO_(2)/PDMS super-hydrophobic composite coating on the surface of Q235.The morphology,microstructure,and surface characteristics were investigated by field emission scanning electron microscope(FESEM,JSM-7610FPlus),confocal laser scanning confocal microscope(CLSM,KEYENCE/VK-X1100),energy dispersive X-ray spectrometer(EDS),contact angle measuring instrument(SDC-100),sandpaper abrasion test,knife scratching and tape stripping test.The anti-corrosion property of the SiO_(2)/PDMS super-hydrophobic coating was evaluated by electrochemical impedance spectrum(EIS)and Tafel polarization curve with 3.5wt.%sodium chloride solution as the corrosive medium.The FESEM,CLSM and EDS characterization results showed that the SiO_(2)/PDMS super-hydrophobic coating had been successfully coated on the surface of Q235,and the surface of Q235 became rough and presented a strewn gully structure after the super-hydrophobic coating modification.The average roughness was 2.2μm.The surface energy of coating was only 5.6 mJ/m2,the contact angle was 152.6°,and the coating remained super-hydrophobic after 15 cycles of sandpaper wear and 30 cycles of taping and peeling,indicating that the surface of Q235 had excellent super-hydrophobicity.In addition,the EIS results showed that the introduction of SiO_(2)/PDMS super-hydrophobic coating on the surface of Q235 increased the impedance value by two orders of magnitude and decreased the capacitance value by six orders of magnitude.The Tafel curve showed that the corrosion potential of super-hydrophobic coating/Q235 was 0.4192 V higher than that of the bare Q235,the corrosion current was reduced by three orders of magnitude,and the protection efficiency of the coating could be as high as 99.8%,demonstrating that the coating had excellent corrosion resistance.In addition,the durability test showed that the SiO_(2)/PDMS coating retained super-hydrophobicity and excellent corrosion resistance after a week of immersion in corrosion solution,implying that the SiO_(2)/PDMS coating had good anti-corrosion durability.In conclusion,with PDMS as hydrophobic coating and SiO_(2)nanoparticles as filler to construct rough surface,a stable SiO_(2)/PDMS super-hydrophobic coating can be prepared on the surface of Q235 by a simple dipping and pulling process.The dense PDMS coating plays a shielding role on the corrosive solution,and its excellent adhesion makes it become the intermediate bridge between the metal substrate and SiO_(2).The introduction of nano-sized SiO_(2)makes the surface of Q235 show a rough structure of microscopic convex,and enhances the stability of the system.The synergistic effect of PDMS and SiO_(2)realizes the transformation from hydrophilic to super-hydrophobic surface of Q235 and improves the corrosion resistance of Q235.This study provides a facile method to construct a robust super-hydrophobic surface on metal surface,which is expected to expand the application of metal in harsh environment.
作者
于元昊
董玉花
邢静
陈亚敏
宁浩良
赵彤
彭淑鸽
YU Yuan-hao;DONG Yu-hua;XING Jing;CHEN Ya-min;NING Hao-liang;ZHAO Tong;PENG Shu-ge(Luoyang Key Laboratory of Industrial Waste Resource Utilization,School of Chemistry&Chemical Engineering,Henan University of Science and Technology,Henan Luoyang 471000,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2023年第9期209-219,共11页
Surface Technology
基金
国家自然科学基金(22175057)。
