Journal article
Mapping the Stability and Curvature of Emulsions of H2O and Supercritical CO2 with Interfacial Tension Measurements
Journal of dispersion science and technology, Vol.23(1-3), pp.65-80
2002
DOI: 10.1080/01932690208984190
Abstract
The stability and curvature of emulsions of H2O and CO2 are reported and analyzed in terms of measurements of interfacial tension versus formulation variables, including salinity, CO2 density, temperature and pH. Among the surfactants studied are, quaternary ammonium cationic ones with perfluoropolyether tails, block copolymer ionomers and a poly(hydroxyethyl methacrylate) with polydimethylsiloxane tails, and a nonionic ethylene oxide surfactant with a fluoroalkane tail. The interfacial tension measurements were made at surfactant concentrations from 0.05 to 1.0 wt% with a variable-volume pendant drop tensiometer up to 345 bar and 363°K. As a formulation variable was varied, the system reached a balanced state characterized by a minimum in interfacial tension, a loss in emulsion stability and in some cases an inversion from a W/C to C/W emulsion. Here the Marangoni-Gibbs stabilization weakens, and also it becomes easy to bend and rupture the surfactant monolayer, causing coalescence. Except in the case of the nonionic fluorinated surfactant abruptly due to clouding of the surfactant out of the CO2 phase. For PFPE-TMAA, the plot of y versus surfactant concentration revealed both pre-micellar aggregates and a critical microemulsion, each of which was dependent on salinity.
Details
- Title: Subtitle
- Mapping the Stability and Curvature of Emulsions of H2O and Supercritical CO2 with Interfacial Tension Measurements
- Creators
- Petros PsathasEdward SanderMin Young LeeKwon Taek LimKeith Johnston
- Resource Type
- Journal article
- Publication Details
- Journal of dispersion science and technology, Vol.23(1-3), pp.65-80
- DOI
- 10.1080/01932690208984190
- ISSN
- 0193-2691
- eISSN
- 1532-2351
- Language
- English
- Date published
- 2002
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Orthopedics and Rehabilitation; Craniofacial Anomalies Research Center; Chemical and Biochemical Engineering
- Record Identifier
- 9984197212602771
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