This title appears in the Scientific Report :
2012
Please use the identifier:
http://dx.doi.org/10.1039/C1SM06533E in citations.
Please use the identifier: http://hdl.handle.net/2128/7395 in citations.
Structure and dynamics of balanced supercritical CO2-microemulsions
Structure and dynamics of balanced supercritical CO2-microemulsions
Balanced scCO(2)-microemulsions contain equal volumes of water and CO2 and are a novel class of microemulsions of substantial interest for both fundamental research and technical applications. One existing feature of these systems is that the solvent quality of scCO(2), and hence the overall microem...
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Personal Name(s): | Klostermann, M. |
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Strey, R. / Sottmann, T. / Schweins, R. / Lindner, P. / Holderer, O. / Monkenbusch, M. / Richter, D. | |
Contributing Institute: |
Neutronenstreuung; ICS-1 Neutronenstreuung; JCNS-1 JCNS-FRM-II; JCNS-FRM-II |
Published in: | Soft matter, 8 (2012) S. 797 - 807 |
Imprint: |
Cambridge
Royal Society of Chemistry (RSC)
2012
|
Physical Description: |
797 - 807 |
DOI: |
10.1039/C1SM06533E |
Document Type: |
Journal Article |
Research Program: |
Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung |
Series Title: |
Soft Matter
8 |
Subject (ZB): | |
Link: |
Get full text Published under German "Allianz" Licensing conditions on 2011-11-14. Available in OpenAccess from 2012-11-14 |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/7395 in citations.
Balanced scCO(2)-microemulsions contain equal volumes of water and CO2 and are a novel class of microemulsions of substantial interest for both fundamental research and technical applications. One existing feature of these systems is that the solvent quality of scCO(2), and hence the overall microemulsion properties, is tuned simply by adjusting pressure, which is not possible with "classical" microemulsions containing oil instead of CO2. Motivated by this, we systematically investigated the phase behavior, the microstructure, and the dynamics of balanced microemulsion systems of the type H2O-CO2-Zonyl FSO 100/Zonyl FSN 100. In systematic phase behavior studies, we found that upon increasing pressure, CO2 and water are more efficiently solubilized. Small angle neutron scattering (SANS) experiments were conducted in order to determine the topology and the length scales of the underlying microstructure. The results obtained strongly suggest the existence of bicontinuously structured microemulsions with an adjustable characteristic length scale of up to 330 angstrom. From a quantitative analysis of the SANS data, we found that at a fixed microemulsion composition the stiffness of the surfactant membrane is increased solely by increasing the pressure, whereby the renormalization corrected (i.e. bare) bending rigidity kappa(0), SANS rises from kappa(0,SANS) 0.88 k(B)T at 200 bar to 0.93 k(B)T at 300 bar. These findings were confirmed with high pressure neutron spin echo experiments. |