The influence of organically intercalated montmorillonites on the interfacial tension and structure of oil-in-water nanoemulsions

The properties of O/W emulsions can be improved by the addition of nanomaterials. To explore the influence of organically intercalated montmorillonites (OMts) on the properties of O/W emulsions, we introduced an OMt into a nanoemulsion as a co-stabilizer with the quaternary ammonium Gemini cationic surfactant (G16-2-16) and nonionic lauryl polyoxyethylene ether (Brij 30). The influence of the organically intercalated montmorillonite (OMt) on the properties, such as the interfacial tension, zeta potential, stability, conductivity and morphology of the droplets, of the nanoemulsions was investigated. The results indicate obvious synergistic effects of OMt with G16-2-16. At the concentration of 0.15% w/v G16-2-16, ultralow interfacial tension (IFT) of the O/W results in the formation of nanoemulsions in a much shorter time with 3.4 × 10-3% w/v OMt than that in the case of without OMt; however, at the concentration of 0.2% w/v G16-2-16, the interfacial tension of the O/W increased upon the addition of 3.4 × 10-3% w/v OMt. In addition, light transmission measurements showed that the transmission of the nanoemulsions varied with temperature, and the process was reversible. The mechanisms of these phenomena were analyzed and confirmed by TEM.