Silicone oil-based Pickering emulsion stabilized by triethoxy(octyl)silane-modified silica from rice husk ash

Abstract

This study explores silicone oil-based Pickering emulsions stabilized by triethoxy(octyl)silane-modified silica particles sourced from rice husk. Native silica particles exhibit an amorphous structure, as shown by X-ray diffraction. Change in surface morphology, observed through scanning electron microscopy (SEM), and the presence of C–H groups identified via Fourier transform infrared spectroscopy (FTIR) confirm the modification of silica derivatives. BET analysis reveals that both native and modified silica are mesoporous. Further analysis indicates a significant reduction in the surface area of triethoxy(octyl)silane-modified silica compared to unmodified silica, attributed to surface clustering, while particle size and pore volume increased. The emulsion stabilization mechanism involves steric and condensation processes, with stability against coalescence due to the irreversible adsorption of particles at the interface and droplet surface coating. This study demonstrates that triethoxy(octyl)silane-modified silica particles from rice husk hold potential for cosmetic and food applications.