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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACPD</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics Discussions</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACPD</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7375</issn>
<publisher><publisher-name>Copernicus GmbH</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acpd-8-5235-2008</article-id>
<title-group>
<article-title>A combined particle trap/HTDMA hygroscopicity study of mixed inorganic/organic aerosol particles</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zardini</surname>
<given-names>A. A.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sjogren</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Marcolli</surname>
<given-names>C.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Krieger</surname>
<given-names>U. K.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Gysel</surname>
<given-names>M.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Weingartner</surname>
<given-names>E.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Baltensperger</surname>
<given-names>U.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Peter</surname>
<given-names>T.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institute for Atmospheric and Climate Science, ETH, CH-8092 Zurich, Switzerland</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, CH-5232 Villigen, Switzerland</addr-line>
</aff>
<pub-date pub-type="epub">
<day>12</day>
<month>03</month>
<year>2008</year>
</pub-date>
<volume>8</volume>
<issue>2</issue>
<fpage>5235</fpage>
<lpage>5268</lpage>
<permissions>
<license xlink:type="simple">
<license-p>This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
</license>
</permissions>
<self-uri xlink:href="http://www.atmos-chem-phys-discuss.net/8/5235/2008/acpd-8-5235-2008.html">This article is available from http://www.atmos-chem-phys-discuss.net/8/5235/2008/acpd-8-5235-2008.html</self-uri>
<self-uri xlink:href="http://www.atmos-chem-phys-discuss.net/8/5235/2008/acpd-8-5235-2008.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/8/5235/2008/acpd-8-5235-2008.pdf</self-uri>
<abstract>
<p>Atmospheric aerosols are often mixtures of inorganic
and organic material. Organics can represent a large fraction of the total aerosol mass
and are comprised of water-soluble and insoluble compounds.
Increasing attention was paid in the last decade
to the capability of mixed inorganic/organic aerosol particles
to take up water (hygroscopicity).
We performed hygroscopicity measurements
of internally mixed particles containing ammonium sulfate and carboxylic acids
(citric, glutaric, adipic acid)
in parallel with an electrodynamic balance (EDB)
and a hygroscopicity tandem differential mobility analyzer (HTDMA).
The organic compounds were chosen to represent three distinct physical states.
During hygroscopicity cycles covering hydration and dehydration
measured by the EDB and the HTDMA,
pure citric acid remained always liquid,
adipic acid remained always solid,
while glutaric acid could be either.
We show that the hygroscopicity of mixtures of the above compounds is well described
by the Zdanovskii-Stokes-Robinson (ZSR) relationship as long as the two-component particle is completely liquid
in the ammonium sulfate/citric acid and in the ammonium sulfate/glutaric acid cases.
However, we observe significant discrepancies compared to what is expected from bulk thermodynamics
when a solid component is present.
We explain this in terms of a complex morphology resulting
from the crystallization process leading to veins, pores,
and grain boundaries which allow for water sorption in excess
of bulk thermodynamic predictions caused by the inverse Kelvin effect on concave surfaces.</p>
</abstract>
<counts><page-count count="34"/></counts>
</article-meta>
</front>
<body/>
<back>
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