DOI: 10.1073/pnas.1915660117
论文题名: The surface tension of surfactant-containing; finite volume droplets
作者: Bzdek B.R. ; Reid J.P. ; Malila J. ; Prisle N.L.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2020
卷: 117, 期: 15 起始页码: 8335
结束页码: 8343
语种: 英语
英文关键词: Aerosol
; Cloud condensation nuclei
; Cloud droplet number concentration
; Surface tension
; Surfactant
Scopus关键词: surfactant
; water
; aerosol
; Article
; atmosphere
; chemical reaction
; concentration (parameter)
; cooling
; laboratory test
; measurement
; morphology
; physical chemistry
; physical model
; prediction
; priority journal
; spray drying
; surface tension
; wettability
英文摘要: Surface tension influences the fraction of atmospheric particles that become cloud droplets. Although surfactants are an important component of aerosol mass, the surface tension of activating aerosol particles is still unresolved, with most climate models assuming activating particles have a surface tension equal to that of water. By studying picoliter droplet coalescence, we demonstrate that surfactants can significantly reduce the surface tension of finite-sized droplets below the value for water, consistent with recent field measurements. Significantly, this surface tension reduction is droplet size-dependent and does not correspond exactly to the macroscopic solution value. A fully independent monolayer partitioning model confirms the observed finite-size-dependent surface tension arises from the high surface-to-volume ratio in finite-sized droplets and enables predictions of aerosol hygroscopic growth. This model, constrained by the laboratory measurements, is consistent with a reduction in critical supersaturation for activation, potentially substantially increasing cloud droplet number concentration and modifying radiative cooling relative to current estimates assuming a water surface tension. The results highlight the need for improved constraints on the identities, properties, and concentrations of atmospheric aerosol surfactants in multiple environments and are broadly applicable to any discipline where finite volume effects are operative, such as studies of the competition between reaction rates within the bulk and at the surface of confined volumes and explorations of the influence of surfactants on dried particle morphology from spray driers. © This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164248
Appears in Collections: 气候变化与战略
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作者单位: Bzdek, B.R., School of Chemistry, University of Bristol, Bristol, BS8 1TS, United Kingdom; Reid, J.P., School of Chemistry, University of Bristol, Bristol, BS8 1TS, United Kingdom; Malila, J., Nano and Molecular Systems Research Unit, University of Oulu, Oulu, 90014, Finland; Prisle, N.L., Nano and Molecular Systems Research Unit, University of Oulu, Oulu, 90014, Finland
Recommended Citation:
Bzdek B.R.,Reid J.P.,Malila J.,et al. The surface tension of surfactant-containing; finite volume droplets[J]. Proceedings of the National Academy of Sciences of the United States of America,2020-01-01,117(15)