Advanced

Complex three-dimensional self-assembly in proxies for atmospheric aerosols

Pfrang, C.; Rastogi, K.; Cabrera-Martinez, E. R.; Seddon, A. M.; Dicko, C. LU ; Labrador, A. LU ; Plivelic, T. S. LU ; Cowieson, N. and Squires, A. M. (2017) In Nature Communications 8(1).
Abstract

Aerosols are significant to the Earth's climate, with nearly all atmospheric aerosols containing organic compounds that often contain both hydrophilic and hydrophobic parts. However, the nature of how these compounds are arranged within an aerosol droplet remains unknown. Here we demonstrate that fatty acids in proxies for atmospheric aerosols self-assemble into highly ordered three-dimensional nanostructures that may have implications for environmentally important processes. Acoustically trapped droplets of oleic acid/sodium oleate mixtures in sodium chloride solution are analysed by simultaneous synchrotron small-angle X-ray scattering and Raman spectroscopy in a controlled gas-phase environment. We demonstrate that the droplets... (More)

Aerosols are significant to the Earth's climate, with nearly all atmospheric aerosols containing organic compounds that often contain both hydrophilic and hydrophobic parts. However, the nature of how these compounds are arranged within an aerosol droplet remains unknown. Here we demonstrate that fatty acids in proxies for atmospheric aerosols self-assemble into highly ordered three-dimensional nanostructures that may have implications for environmentally important processes. Acoustically trapped droplets of oleic acid/sodium oleate mixtures in sodium chloride solution are analysed by simultaneous synchrotron small-angle X-ray scattering and Raman spectroscopy in a controlled gas-phase environment. We demonstrate that the droplets contained crystal-like lyotropic phases including hexagonal and cubic close-packed arrangements of spherical and cylindrical micelles, and stacks of bilayers, whose structures responded to atmospherically relevant humidity changes and chemical reactions. Further experiments show that self-assembly reduces the rate of the reaction of the fatty acid with ozone, and that lyotropic-phase formation also occurs in more complex mixtures more closely resembling compositions of atmospheric aerosols. We suggest that lyotropic-phase formation likely occurs in the atmosphere, with potential implications for radiative forcing, residence times and other aerosol characteristics.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nature Communications
volume
8
issue
1
publisher
Nature Publishing Group
external identifiers
  • scopus:85034994168
  • wos:000416229300010
ISSN
2041-1723
DOI
10.1038/s41467-017-01918-1
language
English
LU publication?
yes
id
f9f4bece-2db2-422d-bd42-e90bb6537683
date added to LUP
2017-12-07 14:24:30
date last changed
2018-08-26 05:00:12
@article{f9f4bece-2db2-422d-bd42-e90bb6537683,
  abstract     = {<p>Aerosols are significant to the Earth's climate, with nearly all atmospheric aerosols containing organic compounds that often contain both hydrophilic and hydrophobic parts. However, the nature of how these compounds are arranged within an aerosol droplet remains unknown. Here we demonstrate that fatty acids in proxies for atmospheric aerosols self-assemble into highly ordered three-dimensional nanostructures that may have implications for environmentally important processes. Acoustically trapped droplets of oleic acid/sodium oleate mixtures in sodium chloride solution are analysed by simultaneous synchrotron small-angle X-ray scattering and Raman spectroscopy in a controlled gas-phase environment. We demonstrate that the droplets contained crystal-like lyotropic phases including hexagonal and cubic close-packed arrangements of spherical and cylindrical micelles, and stacks of bilayers, whose structures responded to atmospherically relevant humidity changes and chemical reactions. Further experiments show that self-assembly reduces the rate of the reaction of the fatty acid with ozone, and that lyotropic-phase formation also occurs in more complex mixtures more closely resembling compositions of atmospheric aerosols. We suggest that lyotropic-phase formation likely occurs in the atmosphere, with potential implications for radiative forcing, residence times and other aerosol characteristics.</p>},
  articleno    = {1724},
  author       = {Pfrang, C. and Rastogi, K. and Cabrera-Martinez, E. R. and Seddon, A. M. and Dicko, C. and Labrador, A. and Plivelic, T. S. and Cowieson, N. and Squires, A. M.},
  issn         = {2041-1723},
  language     = {eng},
  month        = {12},
  number       = {1},
  publisher    = {Nature Publishing Group},
  series       = {Nature Communications},
  title        = {Complex three-dimensional self-assembly in proxies for atmospheric aerosols},
  url          = {http://dx.doi.org/10.1038/s41467-017-01918-1},
  volume       = {8},
  year         = {2017},
}