The nucleation mechanism of succinic acid involved sulfuric acid - dimethylamine in new particle formation
The nucleation mechanism of succinic acid involved sulfuric acid - dimethylamine in new particle formation
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DOI：
10.1016/j.atmosenv.2021.118683
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发表时间：
2021-08
影响因子：
5
通讯作者：
Zhong-Quan Wang;Yirong Liu;Chunyu Wang;Shuai Jiang;Yajuan Feng;Teng Huang;Wei Huang
中科院分区：
文献类型：
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作者：
Zhong-Quan Wang;Yirong Liu;Chunyu Wang;Shuai Jiang;Yajuan Feng;Teng Huang;Wei Huang
琥珀酸（SUA）是一种常见的二羧酸，经常在气溶胶中观察到。了解琥珀酸在大气新粒子形成中的作用，对于研究复杂的成核机制至关重要。本文采用高精度量子化学计算和大气团簇动力学模拟（ACDC）方法研究了（SA）x（SUA）y（DMA）z（0 = x，y，z ≤ 3）多组分体系的成核机制.最稳定的分子结构表明，SUA可以通过氢键和质子转移作用与SA-DMA体系形成相对稳定的簇合物。与SA分子类似，当过量的DMA分子可用时，SUA可以向DMA提供质子。ACDC模拟表明，SUA可以促进团簇的形成，特别是在低硫酸浓度和高琥珀酸浓度下。此外，从含SUA体系中流出的团簇主要是沿沿着非对角线方向（酸分子的数目大于碱分子的数目）流出，这与纯SA-DMA体系不同。这些团簇足够稳定，可以以相当高的浓度存在，并且可以成为生长成更大尺寸的平台。这种有机酸参与的簇形成可以解释在低硫酸浓度和高有机酸浓度下的高成核速率。
Succinic acid (SUA) is a common dicarboxylic acid frequently observed in aerosols. Understanding the role of succinic acid in atmospheric new particle formation is essential to study the complicated nucleation mechanism. In this study, high-precision quantum chemical calculations and atmospheric clusters dynamic code (ACDC) simulations are used to investigate the nucleation mechanism of the (SA)x(SUA)y(DMA)z(0 = x, y, z ≤ 3) multicomponent system. The most stable molecular structures show that SUA can form relatively stable clusters with the SA-DMA system by hydrogen bond and proton-transfer interactions. Similar to SA molecules, SUA can provide protons to DMA when excess DMA molecules are available. ACDC simulations indicate that SUA can contribute to the cluster formation, especially at low sulfuric acid concentration and high succinic acid concentration. Moreover, the main cluster flux out of the SUA-containing system is along the non-diagonal (the number of acid molecules is greater than that of base molecules), which is different from the pure SA-DMA system. These clusters are stable enough to be present at a fairly high concentration, and could be a platform for growth into the larger sizes. This organic acid involved cluster formation may explain high nucleation rate at low sulfuric acid concentration and high organic acid concentration.