Semi-batch process is the main protocol used to obtain this kind of products. It consists of two steps, the first one is aqueous phase incorporation into the surfactant-oil mixture phase under given mixing conditions, and the second one is the homogenization step in the same equipment (with possible modifications in the mixing conditions).
We studied process variables influence on rheological characteristics of highly concentrated water-in-oil emulsions.The studied mixing variables were: aqueous phase mass flow rate (Qw) and agitation speed (N) during the incorporation step, and homogenization speed (N') and homogenization time (th) in the second step. The system under study is composed of n-dodecane as oily phase, deionized water as aqueous phase and sorbitan monooleate (Span 80) as emulsifying agent. The rheological behavior of highly concentrated water-in-oil emulsions was evaluated, one hour after their preparation at room temperature, through mechanical spectrometry in the linear viscoelastic domain.
Results show a relationship between the rheological characteristics of highly concentrated water-in-oil emulsions (elastic modulus (G')) and energy consumption during emulsification process (E). This relationship can be described by GaE0.6. In addition, we observed that energy consumption in homogenization step was higher that in incorporation step.