Characterization of Vesicle and Microemulsion Microstructures
Abstract
We have determined micellar aggregation numbers for a number of single- and double-chain surfactants using time-resolved fluorescence quenching and small angle neutron scattering as functions of surfactant concentration, chain length and temperature. The force between dialkyldimethylammonium bromide and acetate bilayers was measured with the surface forces apparatus as a function of added salt and temperature. Using atomic force microscopy we obtained images of normal and interdigitated bilayers. We identified a new mechanism for emulsification in which a W/O microemulsion inverts to a O/W macroemulsion upon contact with water. We characterized high internal phase emulsions and related their structures to the HLB temperature of the surfactant. We prepared the first reversed vesicles containing water shells separated by well-defined hydrocarbon interior and exterior phases. We demonstrated how both normal and reversed micelles can be prepared from the same oil/water/surfactant system near the HLB temperatures of the surfactant by simply varying the concentration of components. Self-Assembly, Amphiphiles, Reversed Vesicles, Surface Forces Apparatus, Atomic Force Microscopy, High Internal Volume Phase Emulsions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1992
- Accession Number
- ADA257036
Entities
People
- D. F. Evans
Organizations
- University of Minnesota