新喀里多尼亚弧菌胞外聚合物对硫酸中Q235碳钢的缓蚀作用

Inhibition Effect of Exopolysaccharide of Vibrio Neocaledonicus sp.on Q235 Carbon Steel in Sulphuric Acid Solution

采用电化学阻抗测试、极化曲线测试和扫描电镜观察等方法研究了在25℃条件下新喀里多尼亚弧菌胞外聚合物(EPS)对Q235碳钢在0.5 mol/L H2SO4溶液中的缓蚀作用。结果表明:该弧菌EPS能够在碳钢表面形成一层较为致密的Fe-EPS保护层,可有效抑制H_2SO_4溶液对Q235钢的腐蚀。随着EPS浓度的增加,缓蚀效率增大;当EPS浓度为1.0 g/L时,缓蚀效率最高。EPS在Q235钢表面的吸附为自主的化学吸附且符合Langmuir吸附模型。通过Fourier红外吸收光谱确定了该EPS的成分。

The inhibition effect of exopolysaccharide（EPS） extracted from Vibrio neocaledonicus sp. on carbon steel Q235 has been studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy（EIS） and scanning electronic microscopy（SEM）. The results showed that EPS could inhibit effectively the corrosion for Q235 steel in solution of 0.5 mol/L H2SO4 because of that a film of Fe-EPS could formed on carbon steel during the corrosion process. The inhibition efficiency reached the maximum when the concentration of EPS was 1.0 g/L. The absorption of EPS on Q235 steel was chemisorption and obeyed the Langmuir adsorption isotherm. The composition of EPS was identified by using FTIR.