The phase behaviour and stability of an environmentally friendly oil-in-water emulsion produced using Balanites aegyptiaca oil and green emulsifiers

Due to environmental concerns about extensively using chemical emulsifiers and hydrocarbon oil in emulsion systems formation, recent research has shifted to using natural emulsifiers and oil. This study produced green emulsion using Balanites aegyptiaca oil and various bio-emulsifiers (such as sodium alginate, carboxymethylcellulose, guar gum, and Saponin). Phase behavior and stability of the emulsion were tested at different NaCl concentrations over one month of ageing. The emulsion was also produced using Balanites aegyptiaca oil and synthetic emulsifiers (Tween 80 and Triton X-100). The critical micelle concentrations of emulsifiers were determined and used as the fixed concentration for the green emulsion preparation. In addition, the properties of aqueous emulsifiers, particularly interfacial tension and contact angle, were studied for solid-liquid and liquid-liquid systems. Phase behaviour stability test confirmed the potential of sodium alginate and carboxymethylcellulose in the formation of emulsions with 5.5 ml volume, Winsor type II phase behavior similar to synthetic emulsifier Triton X-100 at different NaCl concentrations was obtained. Furthermore, the stability of the formed emulsions is independent of the NaCl concentration ranging from 0.5 to 3.5 g/100 ml. The equilibrium time for all the as-prepared green emulsion systems was one month. Depending on the type of emulsifier, the phase stability of the formulated emulsion systems prepared in this study ranks from (Sodium Alginate ~ Carboxylmethycellulose ~ Triton X-100~Tween 80~Saponin ~ Guar Gum). The findings revealed the potential to produce green emulsion using Balanites aegyptiaca oil and bio-emulsifier. Such an environmentally friendly emulsion system can be utilized in enhanced oil recovery.