Development and characterisation of a continuous phase based on a fumed silica and a green surfactant with emulsion applications

Abstract

Different ecological continuous phases were developed as a function of a green surfactant (Amidet N) and a fumed silica (Aerosil 200) concentration. The suitability of these systems was analysed by means of Small Amplitude Oscillatory Shear tests, flow curves, Cryo-SEM (Scanning Electron Microscopy) and the Multiple Light Scattering technique.An important rheological change in viscoelastic and flow properties was detected from 8 wt% to 9 wt% for binary systems of Aerosil/water. This rheological change was related to the interaction of Aerosil chains, which was reflected through the Cryo-SEM. As a consequence of the microstructure and, therefore, rheological properties, an increase in the physical stability of the more concentrated systems was observed. The addition of Amidet N provoked an increase in viscoelastic properties related to the effective interaction between Aerosil chains. Finally, a stable lemongrass essential oil-in-water was developed. In this study, the role of Aerosil 200 as rheological modified and stabilizer has been studied. On top of that, the synergic rheological effect between this fumed silica and Amidet N has been proved.