Tang Xiao, Li Juanjuan, Wu Yuan, Hu Hao, Ma Chao Ran, Li Yan, Fan Haiming
Shandong Key Laboratory of Oilfield Chemistry, China University of Petroleum (East China), Qingdao, China.
School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, China.
Front Chem. 2021 Apr 14;9:610738. doi: 10.3389/fchem.2021.610738. eCollection 2021.
The electrochemical formation mechanism of microdroplets formed around a primary droplet of 3.5% NaCl solution on an iron-plated film was investigated by quartz crystal microbalance (QCM) and concentric three-electrode array (CTEA) measurements. During the initial stage, the microdroplets mainly originate from evaporation owing to cathodic polarization and electric current of the localized corrosion cell under the primary droplet. The maximal electrochemical potential difference between the anode and cathode was measured to be 0.36 V and acted as the driving force for the formation of microdroplets. The maximums of anodic and cathodic electric current density of pure iron under the NaCl droplet are 764 and -152 μA/cm, respectively. Propagation of microdroplets in the developing stage attributes to horizontal movement of the electrolyte, water evaporation, and recondensation from primary and capillary condensation from moist air. The results of the study suggest that the initiation and propagation of microdroplets could promote and accelerate marine atmospheric corrosion.
通过石英晶体微天平（QCM）和同心三电极阵列（CTEA）测量，研究了在镀铁薄膜上3.5% NaCl溶液的初级液滴周围形成的微滴的电化学形成机制。在初始阶段，微滴主要源于初级液滴下方局部腐蚀电池的阴极极化和电流导致的蒸发。阳极和阴极之间的最大电化学电位差经测量为0.36 V，作为微滴形成的驱动力。NaCl液滴下纯铁的阳极和阴极电流密度最大值分别为764和 -152 μA/cm²。微滴在发展阶段的传播归因于电解质的水平移动、水的蒸发以及初级液滴的再凝结和潮湿空气中的毛细凝结。研究结果表明，微滴的起始和传播会促进和加速海洋大气腐蚀。
