Influence of phase orientation on dynamic interfacial tension measured by drop volume tensiometry.

Abstract

During surfactant flooding and caustic water flooding, the interfacial tension (IFT) between the oil and the aqueous phase plays an important role. In the present thesis, the effect of phase orientation on the dynamic IFT between the two phases has been investigated by using the method of drop volume tensiometry (DVT). Two distinct model systems have been studied. The first system is formed by the partially miscible system composed of butanol-1 and water. With butanol-rich (butanol-1 saturated by water) as the dispersed phase and water-rich (water saturated by butanol-1) as the continuous phase, the IFT is 1.70 $\pm$ 0.02 mN/m. The IFT for water-rich as dispersed phase is almost identical at 1.72 $\pm$ 0.03 mN/m. Addition of a surfactant, sodium dodecyl sulfate (SDS), to the system has also been studied. The influence of phase orientation on the critical micelle concentration has also been investigated. The results indicate that the critical micelle concentration is lower when the surfactant is added into the continuous phase than when it is added into the dispersed phase. The second system is formed by two immiscible liquids, hexadecane and water. In measuring the dynamic IFT of this system, the effect of phase orientation is found to be similar to the first system. It is found that both the ready-made and in situ-formed surfactants can decrease the IFT between oleic phase and aqueous phase, however, the in situ-formed surfactant is apparently more effective in reducing IFT than the ready-made surfactant. (Abstract shortened by UMI.)