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Updated: May 28, 2026
10:06
Microfluidic Fabrication Techniques for High-Pressure Testing of Microscale Supercritical CO2 Foam Transport in Fractured Unconventional Reservoirs
Published on: July 2, 2020
Microstructure of supercritical CO2-in-water microemulsions: a systematic contrast variation study
Michael Klostermann1, Tobias Foster, Ralf Schweins
1Department of Chemistry, University of Cologne, 50939 Cologne, Germany. Michael.Klostermann@uni-koeln.de
Physical Chemistry Chemical Physics : PCCP
|October 15, 2011
Summary
Water-rich microemulsions using CO(2) and surfactants show potential for green chemistry. Their structure, with CO(2)-swollen droplets in water, can be tuned by pressure, influencing properties like elasticity.
Area of Science:
- Green chemistry
- Physical chemistry
- Materials science
Background:
- Water-CO(2)-surfactant microemulsions offer tunable properties via pressure.
- Understanding their phase behavior and microstructure is key for novel solvent applications.
Purpose of the Study:
- Investigate the phase behavior and microstructure of water-rich H(2)O-scCO(2)-surfactant microemulsions.
- Characterize the influence of pressure on microemulsion properties.
- Utilize non-ionic surfactants Zonyl FSO 100 and Zonyl FSN 100.
Main Methods:
- Studied temperature-dependent phase behavior at elevated pressures.
- Employed small-angle neutron scattering (SANS) for microstructure analysis.
- Utilized contrast variation to determine scattering length densities and sub-phase compositions.
- Analyzed scattering data with a new form factor for core/shell particles and Generalized Indirect Fourier Transformation (GIFT).
Main Results:
- Phase behavior aligns with typical non-ionic microemulsions.
- Systems comprise CO(2)-swollen microemulsion droplets dispersed in an aqueous phase.
- Droplet radius increases nearly linearly with CO(2) addition.
- Analytical density profiles were confirmed using GIFT.
Conclusions:
- Water-rich scCO(2)-surfactant microemulsions exhibit predictable phase behavior.
- Microstructure consists of dispersed CO(2)-swollen droplets in a continuous aqueous phase.
- Pressure-induced changes in CO(2) content significantly impact droplet size, offering a method for property tuning.
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