pH响应的TiO_(2)基纳米容器的制备及缓蚀性能

Preparation and Anticorrosion Performance of pH-responsive TiO_(2) Based Nanocontainers

目的提高环氧树脂涂层对钢片的耐腐蚀性。方法采用水热法和NaF刻蚀法合成了中空TiO_(2)纳米颗粒,以此为材料基底,在TiO_(2)内部封装了苯并三氮唑(BTA)缓蚀剂,并以正硅酸乙酯(TEOS)和3-氨丙基三乙氧基硅烷(APTES)为硅源,在封装BTA缓蚀剂的TiO_(2)外表面包覆了硅膜。采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)、X射线光电子能谱仪(EDS)、X射线粉末衍射仪(XRD)、热重分析仪(TGA)及紫外-可见吸收光谱仪(UV-Vis)等,对纳米容器(TiO_(2)@BTA@SiO_(2))的微观形貌、物相和结构进行了表征,并通过UV-Vis测试了纳米容器在不同pH值(2、4、7)下BTA的释放行为。采用极化曲线测定了钢片在不含和含有修饰TiO_(2)的0.3%NaCl溶液中不同pH值下的抗腐蚀行为。结果pH=2时纳米容器中封装的BTA释放率最大,超过90%的BTA在24 h内释放出来,腐蚀抑制率为80.7%。经交流阻抗(EIS)测试表明,在浸泡周期(1~7 d)内epoxy@修饰TiO_(2)涂层的阻抗变化值基本维持在1个数量级以内,并且阻抗性能整体高于空白涂层。结论TiO_(2)@BTA@SiO_(2)纳米颗粒的掺杂提高了环氧树脂涂层的耐腐蚀性能,延长了涂层的使用时间。

This paper aims to enhance the anti-corrosion of epoxy coating to steel sheet.The hollow TiO_(2) nanoparticles were synthesized by hydrothermal reaction and sodium fluoride sculpture.With this TiO_(2) was used as the substrate to load the corrosion inhibitor azimidobenzene(BTA).The TiO_(2) outer shell encapsulated with BTA was modified by a silicon dioxide film with ethylsilicate(TEOS)and(3-aminopropyl)triethoxysilane(APTES)as silicon sources.The microstructure,phase and structure were characterized by scanning electron microscopy(SEM),Fourier transform infrared(FTIR)spectroscopy,X-ray photoelectron spectroscopy(EDS),X-ray powder diffractometer(XRD),thermal gravimetric analyzer(TGA)and ultravioletvisible spectrum(UV-Vis).The release behavior of BTA at different pH values(2,4,7)was investigated use ultraviolet-visible spectrum analysis.The anti-corrosion behavior of steel sheets in 0.3%NaCl solutions without and with modified TiO_(2) at different pH values was measured by polarization curves.The results indicated that when pH values were adjusted to 2,BTA encapsulated in nanocontainers release rate was the highest,approximately 90%of BTA released within 24 h,and the corrosion inhibition rate reached to 80.7%.Studied by using electrochemical impedance spectroscopy(EIS)showed that the epoxy@modified TiO_(2) coating was basically maintained within one order of magnitude during the soaking period(1~7 d)and it had better corrosion resistance than the blank epoxy coating.In conclusion,the doping of TiO_(2)@BTA@SiO_(2) nanoparticles improves the corrosion resistance of epoxy resin coating and prolongs the use time of the coating.