TY - JOUR
T1 - Nucleation mechanisms of iodic acid in clean and polluted coastal regions
AU - Rong, Hui
AU - Liu, Jiarong
AU - Zhang, Yujia
AU - Du, Lin
AU - Zhang, Xiuhui
AU - Li, Zesheng
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/8
Y1 - 2020/8
N2 - In coastal regions, intense bursts of particles are frequently observed with high concentrations of iodine species, especially iodic acid (IA). However, the nucleation mechanisms of IA, especially in polluted environments with high concentrations of sulfuric acid (SA) and ammonia (A), remain to be fully established. By quantum chemical calculations and atmospheric cluster dynamics code (ACDC) simulations, the self-nucleation of IA in clean coastal regions and that influenced by SA and A in polluted coastal regions are investigated. The results indicate that IA can form stable clusters stabilized by halogen bonds and hydrogen bonds through sequential addition of IA, and the self-nucleation of IA can instantly produce large amounts of stable clusters when the concentration of IA is high during low tide, which is consistent with the observation that intense particle bursts were linked to high concentrations of IA in clean coastal regions. Besides, SA and A can stabilize IA clusters by the formation of more halogen bonds and hydrogen bonds as well as proton transfers, and the binary nucleation of IA-SA/A rather than the self-nucleation of IA appears to be the dominant pathways in polluted coastal regions, especially in winter. These new insights are helpful to understand the mechanisms of new particle formation induced by IA in clean and polluted coastal regions.
AB - In coastal regions, intense bursts of particles are frequently observed with high concentrations of iodine species, especially iodic acid (IA). However, the nucleation mechanisms of IA, especially in polluted environments with high concentrations of sulfuric acid (SA) and ammonia (A), remain to be fully established. By quantum chemical calculations and atmospheric cluster dynamics code (ACDC) simulations, the self-nucleation of IA in clean coastal regions and that influenced by SA and A in polluted coastal regions are investigated. The results indicate that IA can form stable clusters stabilized by halogen bonds and hydrogen bonds through sequential addition of IA, and the self-nucleation of IA can instantly produce large amounts of stable clusters when the concentration of IA is high during low tide, which is consistent with the observation that intense particle bursts were linked to high concentrations of IA in clean coastal regions. Besides, SA and A can stabilize IA clusters by the formation of more halogen bonds and hydrogen bonds as well as proton transfers, and the binary nucleation of IA-SA/A rather than the self-nucleation of IA appears to be the dominant pathways in polluted coastal regions, especially in winter. These new insights are helpful to understand the mechanisms of new particle formation induced by IA in clean and polluted coastal regions.
KW - Coastal regions
KW - Complex air pollution
KW - Density functional theory
KW - Halogen bonds
KW - New particle formation
UR - http://www.scopus.com/inward/record.url?scp=85083192454&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2020.126743
DO - 10.1016/j.chemosphere.2020.126743
M3 - Article
C2 - 32464777
AN - SCOPUS:85083192454
SN - 0045-6535
VL - 253
JO - Chemosphere
JF - Chemosphere
M1 - 126743
ER -