Nanoscale Imaging of a Corrosion Reaction: Sulfuric Acid Droplets on Aluminum Surfaces
Nanoscale Imaging of a Corrosion Reaction: Sulfuric Acid Droplets on Aluminum Surfaces
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腐蚀反应的纳米级成像：铝表面上的硫酸液滴
DOI：
10.1021/jp952538a
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
M. Salmeron
中科院分区：
文献类型：
--
作者：
Q. Dai;Jun Hu;A. Freedman;and Gary N. Robinson;M. Salmeron
采用扫描极化力显微镜和常规原子力显微镜对铝在硫酸腐蚀过程中液固两相的形貌变化进行了纳米分辨率的原位成像。酸和金属之间的反应速率在很大程度上取决于相对湿度。在较高的相对湿度下，观察到液滴的急剧扩散，这表明硫酸引起的铝腐蚀。液体层由硫酸铝产品和硫酸的混合物组成。在低相对湿度下，形成硫酸铝沉淀，从未反应的液体酸中分离出来。这种相分离抑制了进一步的腐蚀，与以前使用红外反射吸收光谱的实验结果一致。这些实验结果为气-液-固界面的化学腐蚀机理提供了新的见解。
The morphological changes of the liquid and solid phases occurring during the corrosion of aluminum by sulfuric acid were imaged in situ with nanometer resolution using scanning polarization force microscopy and conventional atomic force microscopy. The rate of reaction between the acid and the metal is highly dependent on the relative humidity. At high relative humidities, a dramatic spreading of the liquid droplets is observed that is indicative of sulfuric acid-induced aluminum corrosion. The liquid layer consists of a mixture of aluminum sulfate product and sulfuric acid. At low relative humidity, an aluminum sulfate precipitate is formed which segregates from the unreacted liquid acid. This phase separation inhibits further corrosion, in agreement with the results of previous experiments using infrared reflection absorption spectroscopy. The results of these experiments offer new insights into the mechanisms of chemical corrosion at gas−liquid−solid interfaces.