Surface Freezing a pathway to stable high internal phase emultion (hipe)

Linear alkanes and surfactants with similar chain lengths, when combined at a given temperature, present a mixed monolayer of ordered molecules. This phenomenon is called surface freezing and can be used to stabilize emulsions.

In this work, the hanging drop method was used to measure interfacial tension as function of temperature and as function of the composition of the oil and aqueous phase to determine the surface freezing temperature. With this temperature determined, it was investigated how it could be used to stabilize HIPEs oil-in-water emulsions.

With variations in concentrations, it was observed that for higher surface freezing temperatures a higher concentration of hexadecanol in the oil phase is necessary. In fact, the emulsions tested showed better stability when kept below freezing temperature.