外加交流电场对薄液膜中氧扩散的影响

Effect of Alternating Electric Field on Diffusion Coefficient of Oxygen in Thin Electrolyte Layer

采用计时电流法测定了交流电场作用下O_2在薄液膜中的扩散系数。考察了计时电流法测定氧扩散系数这一方法在薄液膜体系和电场环境下应用的可行性,研究了薄液膜体系中液膜厚度以及外加电场对氧扩散系数的影响。结果表明,O的扩散系数随着薄液膜厚度的减小而增大,随着交流电场强度的增强而增大。交流电场对O扩散系数的影响可能是其加速了O通过气/液界面到达电极表面的过程。薄的液膜和强的电场会加快金属腐蚀的阴极过程中O的传输,从而加速金属腐蚀。

Effect of an applied alternating electric field on the oxygen diffusion coefficient in thin electrolyte layers on an electrode of stainless steel was investigated by chronoamperometry. The re- sults show that the oxygen diffusion coefficient increased with the decrease in TEL thickness, as well as the increase in AEF strength. The effect of AEF on the oxygen diffusion coefficient is found to be due to that the migration of oxygen form the gas/liquid interface to electrode surface was ac- celerated by the applied electric field. For a thinner electrolyte layer by a stronger applied electric field, the cathodic process of the electrode would be more intensive, which corresponds to higher corrosion rate of metal.