کلثوم ملکشاهی فر

In this study, the effect of anionic sodium dodecyl sulfate surfactant on the InterFacial Tension (IFT) of water and oil that is important in the Enhanced Oil Recovery (EOR) was studied using an experimental method and molecular dynamics simulation. For this purpose, the interfacial tension between the water solution and droplet decane was investigated in two conditions. In the first case, the solution consists of pure water molecules and chimneys, and in the second case, sodium dodecyl sulfate surfactant was added to the solution. In the SDS1 system, interfacial tension decreased from 54.83 mN /m to 7.32 mN /m and in the SDS2 system, the interfacial tension of 59.06 mN /m decreased by 8.28 mN /m. The results showed that the addition of anionic sodium dodecyl sulfate surfactant reduces interfacial tension in the second case. On the other hand, the number of molecules was evaluated and the molecular ratio was affected in the process of decreasing surface tension. The larger the number of water molecules and decane, the greater the ability to reduce the interfacial tension. According to the results, the higher  the number of surfactant molecules with respect to water and alkanes, the more interfacial tension reduction is observed. Also, molecular simulations were performed to investigate the effect of surfactant concentration on interfacial tension at constant water and alkane (16 surfactant molecules, 120 molecules of dihydrates, and 800 molecules of water) (SDS3). The results showed that the interfacial tension decreased to 12.66 mN / m which has a lower performance than the SDS1 mode.