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| Titel |
Investigation of Microcrystalline Cellulose as Ice Nucleus in Immersion Freezing Processes |
| VerfasserIn |
Thomas Häusler, Evgeniya Khaybulkina, Laura Felgitsch, Magdalena Bichler, Hinrich Grothe |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102418
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| Publikation (Nr.) |
 EGU/EGU2015-1734.pdf |
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| Zusammenfassung |
| Aerosol-cloud interactions play an important role in earth’s radiation balance. Aerosol
particles act as cloud condensation nuclei for liquid droplets and/or as ice nuclei for the
formation of ice particles. Previous research in our group has been related to biological ice
nucleation.1-3 Here, we present a proxy for many biological macromolecular substances, i.e.
microcrystalline cellulose. Due to the chemical convenience of cellulose compared to other
biological ice nuclei, basic, but still unknown ice nucleation mechanisms can be
investigated. Cellulose is a polysaccharide consisting of a linear chain of several
hundred to many thousands of β(1/4) linked D-glucose units. It is an important
structural element of the primary cell wall of green plants, many forms of algae and the
oomycetes.
Several types of microcrystalline cellulose were analysed and investigated due to
their physico-chemical properties. Immersion freezing experiments were carried
out in a unique reaction gadget. In this device a water-in-oil suspension (with the
cellulose suspended in the aqueous phase) was cooled till the freezing point and was
observed through a microscope. The results of the immersion freezing experiments of
the different cellulose types showed variable ice nucleation activities depending
on their morphology (e.g. particle size) and their concentration. Further analysis
methods as scanning electron microscopy (SEM) and small angle X-ray scattering
(SAX) were carried out to entirely describe the cellulose and their ice nucleation
activity.
[1] S.Augustin, H. Wex, D. Niedermeier, B. Pummer, H.Grothe, S. Hartmann,
L. Tomsche, T. Clauss, J. Voigtländer, K. Ingatius, and F. Stratmann. Immersion
freezing of birch pollen washing water. Atmospheric Chemistry Physics 2013, 13,
10989-11003
[2] B. Pummer, L. Atanasova, H. Bauer, H. Bernardi, I. S. Druzhinina, J.
Froehlich-Nowoisky, H. Grothe. Spores of many common airborne fungi reveal no ice
nucleation activity in oil immersion freezing experiments. Biogeosciences 2013, 10, 8083-
8091
[3] B. Pummer, H. Baue, J. Bernardi, S. Bleicher, H. Grothe. Suspendable macromolecules
are responsible for ice nucleation activity of birch and conifer pollen. Atmospheric Chemistry
Physics 2012, 12, 2541-2550 |
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