十二烷基苯磺酸钠在模拟混凝土孔隙液中对Q235钢缓蚀及吸附行为研究

Inhibition and Adsorption Behavior of Sodium Dodecyl benzene Sulfonate on Q235 Steel in Simulated Concrete Pore Fluid

采用动电位极化曲线、Mott-Schottky曲线与表面形貌分析等方法研究了十二烷基苯磺酸钠(SDBS)在0.5 mol/L NaCl和饱和Ca(OH)_(2)溶液(SCP)中对Q235钢的缓蚀作用及吸附行为。结果表明,SDBS浓度在0~8.315×10^(-4)mol/L区间,SDBS在模拟混凝土孔隙液中对Q235钢具有较好的缓蚀效果,其缓蚀率随SDBS浓度的增加而增大。室温下添加8.315×10^(-4)mol/L的SDBS其缓蚀率可达85.72%,且温度从298 K升至328 K过程中,缓蚀率逐渐降低。SDBS在Q235钢表面的吸附符合Langmuir型吸附等温式,吸附过程为放热、熵增的自发过程。SDBS在Q235钢表面的吸附是以化学吸附为主的混合吸附。SDBS在Q235钢表面形成的吸附膜将Cl-等侵蚀性离子隔离,抑制了Q235钢腐蚀。

The corrosion inhibition and adsorption behavior of sodium dodecyl benzene sulfonate(SDBS) in the range of 0~8.315×10^(-4) mol/L on Q235 steel in a simulated concrete pore fluid of 0.5 mol/L NaCl saturated Ca(OH)_(2) solution were studied by means of potential polarization curve measurement,Mott-Schottky curve measurement and surface morphology analysis. SDBS has a good corrosion inhibition effect on Q235 steel in the simulated concrete pore fluid, and its corrosion inhibition rate increases with the increase of SDBS concentration. The addition of 8.315×10^(-4) mol/L SDBS has a corrosion inhibition rate of 85.72% at room temperature, and the corrosion inhibition rate gradually decreases when the temperature rises from 298 K to 328 K.The adsorption of SDBS on the surface of Q235 steel conforms to the Langmuir adsorption isotherm. The adsorption process is a spontaneous process of exothermic and entropy increase. The adsorption of SDBS on the surface of Q235 steel is a mixed adsorption based on chemical adsorption. The adsorption film of SDBS formed on the surface of Q235 steel isolates the aggressive ions such as Cl-and inhibits the corrosion of Q235 steel.