Phase Equilibrium And Interaction For Mixed Surfactants Systems

In this thesis, surface tension, viscosity and foam stability were measured for various mixed surfactant solutions and the synergistic effect of mixed surfactants was investigated. The effect of thickness surfactant on the surface activity was studied. The results were shown that the mixed surfactants system is superior to single surfactant system in surface activity and foam property. The foam stability can be improved by adding thickener surfactant and the surface activity was not altered by the thickener surfactant. Oil in water microemulsion system of SDBS/C12E9/alcohol/isooctane/(brine) water was obtained. The phase equilibrium of the microemulsion was studied and the effect of temperature, salt concentration and cosurfactant on the phase equilibrium and solubility was discussed. The microemulson solubility increased with salt concentration and chain longer of cosurfactant. The effect of temperature on the solubility showed nonmonotonicity.