Molecular Imaging Reveals Two Distinct Mixing States of PM2.5 Particles Sampled in a Typical Beijing Winter Pollution Case

作者：Li, Ye; Zhou, Yadong; Guo, Wenxiao; Zhang, Xin; Huang, Ye; He, Erkai; Li, Runkui; Yan, Beizhan; Wang, Hailong; Mei, Fan^*; Liu, Min^*; Zhu, Zihua^*

来源：Environmental Science and Technology, 2023, 57(15): 6273-6283.

DOI：10.1021/acs.est.2c08694

• PM2
• 5
• mixing state
• 3-D molecular imaging
• surface chemistry
• core-shell structure

Mixing states of aerosol particles are crucial for understanding the role of aerosols in influencing air quality and climate. However, a fundamental understanding of the complex mixing states is still lacking because most traditional analysis techniques only reveal bulk chemical and physical properties with limited surface and 3-D information. In this research, 3-D molecular imaging enabled by ToF-SIMS was used to elucidate the mixing states of PM2.5 samples obtained from a typical Beijing winter haze event. In light pollution cases, a thin organic layer covers separated inorganic particles; while in serious pollution cases, ion exchange and an organic-inorganic mixing surface on large-area particles were observed. The new results provide key 3-D molecular information of mixing states, which is highly potential for reducing uncertainty and bias in representing aerosol-cloud interactions in current Earth System Models and improving the understanding of aerosols on air quality and human health.

• 单位
  中国科学院