缓蚀剂吸附行为的电化学及AFM力曲线研究

Study on Adsorption Behavior of Inhibitors by Electrochemical Methods and AFM Force Curves

结合极化曲线,微分电容曲线测试和AFM力曲线技术研究了直链十二胺对氯化钠溶液中铜镍合金的缓蚀行为以及吸附机理。结果表明:十二胺在合金表面形成单分子层吸附膜而起到缓蚀作用。十二胺浓度越大,吸附膜越致密,缓蚀率越高,力曲线上测得的粘附力值也越大。质子化的十二胺在荷负电的合金表面的吸附使电极零电荷电位正移,电荷屏蔽作用使得AFM力曲线上探针与试样之间的长程静电斥力减小。

Polarization curves, differential capacitance curves and AFM force curves were measured to investigate the inhibition and adsorption behaviors of dodecylamine on Cu - Ni alloy in NaCl solutions. The results showed that dodecylamine inhibited corrosion of the alloy by monolayer adsorption on the alloy surface. The adsorption film became denser with the increasing of the dodecylamine concentration, so that the inhibition efficiency increased and also the adhesive forces measured by force curves were enhanced. The adsorption of protonated dodecylamine on the negatively charged surface made the potential of zero charge （PZC） shift to positive direction, and the long-range electrostatic exclusive forces between the AFM tip and the surface were reduced by screening effect of surface charges.