RESUMEN
The effect of molecular structure of four sorbitan monoester surfactants (sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and sorbitan monooleate) on the formation of simple three-component creams is presented. Interfacial properties of the surfactants were determined using a du Nouy tensiometer and rheological properties of selected creams with oscillation stress sweep, creep recovery and viscosity tests. Depending on the composition, sorbitan monolaurate and sorbitan monooleate formed both o/w creams and w/o creams, while sorbitan monopalmitate and sorbitan monostearate formed only o/w creams. Sorbitan monostearate and sorbitan monopalmitate had the smallest cmc and A(cmc) values and they were the most effective surfactants in lowering the interfacial tension. These surfactants formed the most stable and elastic creams with clear linear viscoelastic regions and small compliance values. Sorbitan monolaurate and sorbitan monooleate formed viscous creams without elastic properties.