Fractional crystallization of oil droplets in O/W emulsions dispersed by Synperonic F127.

The aim of this works is to study an oil-in-water emulsion stabilized with a triblock copolymer Synperonic F127 which presents a double size distribution of oil droplets. The emulsions were studied experimentally by means of differential scanning calorimetry (DSC) and dynamic light scattering (DLS). The DSC analysis was carried out focusing on the cooling behavior of the emulsion. The cooling thermograms of the oil-in-water emulsion revealed two crystallization peaks with Gaussian profile; the interesting characteristic is that both peaks are separated in temperature. In accordance to previous works for a single oil dispersed within an aqueous phase, the DSC technique must show a single Gaussian peak of crystallization attributable to a size distribution of droplets. In the present case of emulsions stabilized with 1 g/L of Synperonic F127, the aggregation behavior of triblock as a function of temperature allows to produce an emulsion with a double size droplet distribution. Comparison with emulsions stabilized with 2 and 4 wt% of non-ionic Tween 20 are also presented.