Relationship between the adsorption behavior at the polyol-oil interface and the emulsion features

The adsorption behavior of two lipophilic emulsifiers at the interface between water-oil and polyol (glycerin, 1,3-butanediol)-oil, and the interaction between them and the corresponding emulsion features were investigated. The dynamic interfacial tension (IFT), saturation adsorption amount (Γ∞), Langmuir constant (κ), interfacial critical micelle concentration (CMCIFT), dynamic adsorption capacity, affinity of emulsifier and medium were determined. The experimental results showed that medium had more significant effect on the adsorption behavior of emulsifier than that of emulsifier type. In Glycerol-Mineral oil (Gly-M) and Water-Mineral oil (W-M) systems, PGPH has the large CMCIFT than Span 80 and the the opposite was true in 1,3-butanediol-Mineral oil (BD-M), which was related to the affinity of emulsifiers and medium. The Γ∞ values of emulsifier in Gly-M and W-M were similar, while the differences in CMCIFT and κ were significant. The emulsifier had larger CMCIFT and smaller Γ∞ in BD-M. This has been similarly demonstrated in emulsification, where PGPH could form W/O/W multi-structure emulsions in W-M and single structure emulsions in polyol-mineral oil. Among them, P/O was formed in Gly-M and O/P was formed in BD-M. In the same system, such as Gly-M system, P/O emulsions were both formed with the emulsifier of Span 80 and PGPH, which existed some differences in particle size and stability. Our results provided useful insights into the adsorption mechanism of emulsifier at polyol-oil interfaces and the construction of polyol/oil emulsion systems.