Effects of the compound system of alkali and alkyl glycosides on the stability of oil-in-water emulsions

Abstract

The effects of Na₂CO₃, nonionic surfactant octyldecyl glucoside (APG0810), and inorganic salt addition on the water separation ratio and apparent viscosity of oil-in-water (O/W) emulsions were investigated. The influences of this compound system on the stability of the emulsion and its synergistic mechanism were also analyzed. Results revealed that in the first compound situation, when APG was selected as the main surfactant and had a concentration of 0.1%, the mass concentration of Na₂CO₃ was 0.4%, the emulsion exhibited the strongest stability, and the water separation ratio at 30 °C for 120 min was 20.3%. In the second compound situation, when Na₂CO₃ was used as the main surfactant and had a concentration of 0.1%, the mass concentration of APG was 0.4%, the emulsion displayed the strongest stability, and the water separation ratio at 30 °C for 120 min was 57.8%. The stability of the O/W emulsion increased with increased NaCl addition, and a higher salt concentration corresponded to a lower water separation ratio. After CaCl₂ addition, the apparent viscosity of the emulsion increased sharply, and the O/W emulsion underwent phase inversion to become an water-in-oil (W/O) emulsion. Within the set mass concentration range, increased salt concentration caused the apparent viscosity of the W/O emulsion measured at 50 °C and 30 rpm to decrease gradually but still exceeded 1500 mPa·s.

Keywords:

• APG0810
• inorganic salt
• Na₂CO₃
• oil-in-water emulsion
• stability