Synthesis and optimization of surfactant-stabilized palm oil-based nanoemulsion for enhanced oil recovery

Nanoemulsions have been reported as a suitable alternative for potential use in enhanced oil recovery (EOR) by reducing the interfacial tension of the oil-water system and altering rock wettability. However, their production can be costly and have unstable colloidal properties. Hence, this work is aimed to produce stable oil-in-water nanoemulsion at a lower cost using refined palm oil and surfactants of Tween 60 and Span 80 in.the ratio of 2:1 via ultrasonication method. In this study, response surface methodology (RSM) was used to investigate the effect of surfactant concentration (5 – 30 mL), sonication time (0 – 15 min), and sonication power (0 – 375 W) on droplet size and zeta potential of nanoemulsion as well as an approach to optimize nanoemulsions preparation. The coefficient of determinations for droplets size and zeta potential were 0.8712 and 0.8041, respectively. The optimum conditions for nanoemulsions preparation were 5.0 mL surfactant concentration, 2.9 min sonication time, and 375 W sonication power, which attained nanoemulsion with droplet size of 423.33 nm and zeta potential of -19.37 mV. These results indicate nanoemulsion can be prepared at low cost using refined palm oil within a shorter sonication time and lower sonication power, and it has the potential to be used for EOR application.