Ultralow interfacial tensions and their relation to phase separation in micellar solutions

Preparation of nanoparticles of silver halides, superconductors and magnetic materials using water-in-oil microemulsions as nano-reactors

“…Due to their importance in various technological applications such as enhanced oil recovery, pharmaceutics, cosmetics, and nanoparticle synthesis, the structure and structural transitions of microemulsions have been extensively studied using X-ray and light scattering, ultracentrifugation, spin label probes, dielectric relaxation, fluorescence probes, and neutron scattering [14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

Research on enhanced oil recovery: past, present and future

“…Miller's model indicates that the repulsive forces shift sufficiently with the addition of salt until the aggregates come close enough together to force an actual phase separation at the optimal salinity. His studies indicate that this middle or surfactant phase is water continuous (99). With careful studies using the polarizing microscope, Benton, Fort and Miller (100) showed that there are two distinct structures, i.e., one, at low salinities, and one at the high salinity values.…”

Thermodynamics of microemulsions: Combined effects of dispersion entropy of drops and bending energy of surfactant films

“…As solubilization of oil and water increase under these conditions, interfacial tension decreases (Healy et al 1976). There are also theoretical reasons for believing that tensions should be lower when solubilization and drop size are larger (Miller et al 1977). In view of the above results, it appears that the optimum condition for producing low tensions is when the surfactant film is sufficiently flexible to form a microemulsion phase instead of a lamellar liquid crystal-but not so flexible that solubilization and drop size are greatly decreased.…”

“…As surfactant concentration and the number of drops per unit volume increase, a point may be reached where the microemulsion separates into two phases, one with a high concentration and one with a low concentration of drops (Miller et al 1977). Since the present model applies only in dilute systems, it cannot predict such a phase separation.…”

“…Here we develop an analysis which includes both effects in its predictions of drop size-a property of mioroemulsions important in its own right and because of its relation to the ability to produce the ultralow interfacial tensions so important in oil recovery (Miller et al 1977). The analysis here deals with two situations where a relatively small amount of surfactant and relatively large amounts of oil and water are present.…”