Organic coating reduces hygroscopic growth of phase-separated aerosol particles

Weijun Li; Xiaome Teng; Xiyao Chen; Lei Liu; Liang Xu; Jian Zhang; Yuanyuan Wang; Yue Zhang; Zongbo Shi

doi:10.1021/acs.est.1c05901

Organic coating reduces hygroscopic growth of phase-separated aerosol particles

Weijun Li^*, Xiaome Teng, Xiyao Chen, Lei Liu, Liang Xu, Jian Zhang, Yuanyuan Wang, Yue Zhang, Zongbo Shi

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

41 Downloads (Pure)

Abstract

A large fraction of secondary aerosol particles are liquid–liquid phase-separated with an organic shell and an inorganic core. This has the potential to regulate the hygroscopicity of such particles, with significant implications for their optical properties, reactivity, and lifetime. However, it is unclear how this phase separation affects the hygroscopic growth of the particles. Here, we showed a large variation in hygroscopic growth (e.g., 1.14–1.32 under a relative humidity (RH) of 90%) of particles from the forest and urban atmosphere, which had different average core–shell ratios. For this reason, a controlled laboratory experiment further quantifies the impact of the organic shell on particle growth with different RH values. Laboratory experiments demonstrated that (NH₄)₂SO₄ particles with thicker secondary organic shells have a lower growth factor at an RH below 94%. Organic shells started to deliquesce first (RH > 50%) and the phase changes of sulfate cores from solid to liquid took place at an RH higher than 80% as deliquescence relative humidity of pure (NH₄)₂SO₄. Our study provides the first direct evidence on an individual particle basis that hygroscopic growth behavior of phase-separated particles is dependent on the thickness of organic shells, highlighting the importance of organic coating in water uptake and possible heterogeneous reactions of the phase-separated particles.

Original language	English
Pages (from-to)	16339-16346
Number of pages	8
Journal	Environmental Science and Technology
Volume	55
Issue number	24
Early online date	12 Dec 2021
DOIs	https://doi.org/10.1021/acs.est.1c05901
Publication status	Published - 21 Dec 2021

Bibliographical note

Funding Information:
Cryo-EM characterization was conducted at the Center of Cryo-Electron Microscopy, Zhejiang University, with the assistance of L. Wu. We gratefully acknowledge Shujia Zhang to conduct part of the laboratory experiments. The work was funded by the National Natural Science Foundation of China (91844301 and 42075096) and Zhejiang Provincial Natural Science Foundation of China (LZ19D050001). All the data are presented in the paper.

Publisher Copyright:
© 2021 American Chemical Society

Keywords

aerosol
hygroscopicity
liquid−liquid phase separation
particle phase

ASJC Scopus subject areas

Chemistry(all)
Environmental Chemistry

Access to Document

10.1021/acs.est.1c05901

LiW2021Organic
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science and Technology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: https://doi.org/10.1021/acs.est.1c05901
Accepted author manuscript, 1.18 MBLicence: None: All rights reserved

Cite this

@article{ea3d85d3e8e54bb3b8c07221cdfd027b,

title = "Organic coating reduces hygroscopic growth of phase-separated aerosol particles",

abstract = "A large fraction of secondary aerosol particles are liquid–liquid phase-separated with an organic shell and an inorganic core. This has the potential to regulate the hygroscopicity of such particles, with significant implications for their optical properties, reactivity, and lifetime. However, it is unclear how this phase separation affects the hygroscopic growth of the particles. Here, we showed a large variation in hygroscopic growth (e.g., 1.14–1.32 under a relative humidity (RH) of 90%) of particles from the forest and urban atmosphere, which had different average core–shell ratios. For this reason, a controlled laboratory experiment further quantifies the impact of the organic shell on particle growth with different RH values. Laboratory experiments demonstrated that (NH4)2SO4 particles with thicker secondary organic shells have a lower growth factor at an RH below 94%. Organic shells started to deliquesce first (RH > 50%) and the phase changes of sulfate cores from solid to liquid took place at an RH higher than 80% as deliquescence relative humidity of pure (NH4)2SO4. Our study provides the first direct evidence on an individual particle basis that hygroscopic growth behavior of phase-separated particles is dependent on the thickness of organic shells, highlighting the importance of organic coating in water uptake and possible heterogeneous reactions of the phase-separated particles.",

keywords = "aerosol, hygroscopicity, liquid−liquid phase separation, particle phase",

author = "Weijun Li and Xiaome Teng and Xiyao Chen and Lei Liu and Liang Xu and Jian Zhang and Yuanyuan Wang and Yue Zhang and Zongbo Shi",

note = "Funding Information: Cryo-EM characterization was conducted at the Center of Cryo-Electron Microscopy, Zhejiang University, with the assistance of L. Wu. We gratefully acknowledge Shujia Zhang to conduct part of the laboratory experiments. The work was funded by the National Natural Science Foundation of China (91844301 and 42075096) and Zhejiang Provincial Natural Science Foundation of China (LZ19D050001). All the data are presented in the paper. Publisher Copyright: {\textcopyright} 2021 American Chemical Society",

year = "2021",

month = dec,

day = "21",

doi = "10.1021/acs.est.1c05901",

language = "English",

volume = "55",

pages = "16339--16346",

journal = "Environmental Science and Technology",

issn = "0013-936X",

publisher = "American Chemical Society",

number = "24",

}

TY - JOUR

T1 - Organic coating reduces hygroscopic growth of phase-separated aerosol particles

AU - Li, Weijun

AU - Teng, Xiaome

AU - Chen, Xiyao

AU - Liu, Lei

AU - Xu, Liang

AU - Zhang, Jian

AU - Wang, Yuanyuan

AU - Zhang, Yue

AU - Shi, Zongbo

N1 - Funding Information: Cryo-EM characterization was conducted at the Center of Cryo-Electron Microscopy, Zhejiang University, with the assistance of L. Wu. We gratefully acknowledge Shujia Zhang to conduct part of the laboratory experiments. The work was funded by the National Natural Science Foundation of China (91844301 and 42075096) and Zhejiang Provincial Natural Science Foundation of China (LZ19D050001). All the data are presented in the paper. Publisher Copyright: © 2021 American Chemical Society

PY - 2021/12/21

Y1 - 2021/12/21

N2 - A large fraction of secondary aerosol particles are liquid–liquid phase-separated with an organic shell and an inorganic core. This has the potential to regulate the hygroscopicity of such particles, with significant implications for their optical properties, reactivity, and lifetime. However, it is unclear how this phase separation affects the hygroscopic growth of the particles. Here, we showed a large variation in hygroscopic growth (e.g., 1.14–1.32 under a relative humidity (RH) of 90%) of particles from the forest and urban atmosphere, which had different average core–shell ratios. For this reason, a controlled laboratory experiment further quantifies the impact of the organic shell on particle growth with different RH values. Laboratory experiments demonstrated that (NH4)2SO4 particles with thicker secondary organic shells have a lower growth factor at an RH below 94%. Organic shells started to deliquesce first (RH > 50%) and the phase changes of sulfate cores from solid to liquid took place at an RH higher than 80% as deliquescence relative humidity of pure (NH4)2SO4. Our study provides the first direct evidence on an individual particle basis that hygroscopic growth behavior of phase-separated particles is dependent on the thickness of organic shells, highlighting the importance of organic coating in water uptake and possible heterogeneous reactions of the phase-separated particles.

AB - A large fraction of secondary aerosol particles are liquid–liquid phase-separated with an organic shell and an inorganic core. This has the potential to regulate the hygroscopicity of such particles, with significant implications for their optical properties, reactivity, and lifetime. However, it is unclear how this phase separation affects the hygroscopic growth of the particles. Here, we showed a large variation in hygroscopic growth (e.g., 1.14–1.32 under a relative humidity (RH) of 90%) of particles from the forest and urban atmosphere, which had different average core–shell ratios. For this reason, a controlled laboratory experiment further quantifies the impact of the organic shell on particle growth with different RH values. Laboratory experiments demonstrated that (NH4)2SO4 particles with thicker secondary organic shells have a lower growth factor at an RH below 94%. Organic shells started to deliquesce first (RH > 50%) and the phase changes of sulfate cores from solid to liquid took place at an RH higher than 80% as deliquescence relative humidity of pure (NH4)2SO4. Our study provides the first direct evidence on an individual particle basis that hygroscopic growth behavior of phase-separated particles is dependent on the thickness of organic shells, highlighting the importance of organic coating in water uptake and possible heterogeneous reactions of the phase-separated particles.

KW - aerosol

KW - hygroscopicity

KW - liquid−liquid phase separation

KW - particle phase

UR - http://www.scopus.com/inward/record.url?scp=85121592880&partnerID=8YFLogxK

U2 - 10.1021/acs.est.1c05901

DO - 10.1021/acs.est.1c05901

M3 - Article

AN - SCOPUS:85121592880

SN - 0013-936X

VL - 55

SP - 16339

EP - 16346

JO - Environmental Science and Technology

JF - Environmental Science and Technology

IS - 24

ER -

Organic coating reduces hygroscopic growth of phase-separated aerosol particles

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Fingerprint

Cite this