The transformation of solid atmospheric particles into liquid droplets through heterogeneous chemistry: Laboratory insights into the processing of calcium containing mineral dust aerosol in the troposphere
The transformation of solid atmospheric particles into liquid droplets through heterogeneous chemistry: Laboratory insights into the processing of calcium containing mineral dust aerosol in the troposphere
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DOI：
10.1029/2002gl016563
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发表时间：
2003-02-15
影响因子：
5.2
通讯作者：
Cowin, JP
中科院分区：
文献类型：
--
作者：
Krueger, BJ;Grassian, VH;Cowin, JP
[1]单个碳酸钙颗粒与气相硝酸在293 K反应后，已使用扫描电子显微镜（SEM）和能量色散X射线（EDX）分析作为时间和相对湿度（RH）的函数。碳酸钙向硝酸钙转化的速率在水蒸气存在下显著提高。SEM图像清楚地表明，随着反应的进行，固体CaCO3颗粒转化为球形液滴。该过程通过两步机制发生，包括碳酸钙转化为硝酸钙，然后是硝酸钙产品的潮解。颗粒的相变化以及硝酸和CaCO3在低RH下的显著反应性是产物在低RH下潮解的直接结果。这是第一个实验室研究表明，通过非均相化学固体颗粒到液滴的相变。
[1] Individual calcium carbonate particles reacted with gas-phase nitric acid at 293 K have been followed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) analysis as a function of time and relative humidity (RH). The rate of calcium carbonate to calcium nitrate conversion is significantly enhanced in the presence of water vapor. The SEM images clearly show that solid CaCO3 particles are converted to spherical droplets as the reaction proceeds. The process occurs through a two-step mechanism involving the conversion of calcium carbonate into calcium nitrate followed by the deliquescence of the calcium nitrate product. The change in phase of the particles and the significant reactivity of nitric acid and CaCO3 at low RH are a direct result of the deliquescence of the product at low RH. This is the first laboratory study to show the phase transformation of solid particles into liquid droplets through heterogeneous chemistry.