Nanoemulsions are metastable colloidal dispersions with a wide range of applications in food, cosmetic, and pharmaceutical industries due to their unique structural properties. Nanoemulsions have shown the solid-like behavior at low oil volume fraction, much lower than that in conventional emulsions. The solid-like behavior (i.e., gelation) in nanoemulsions have been reported by adding electrolytes or depletants or upon an increase in temperature. In this research, we study the colloidal gelation of nanoemulsion at a wide range of oil volume fraction and different packing structures of droplets. First, we prepare an initial nanoemulsion with 25% of silicone oil volume fraction dispersed in the aqueous continuous phase containing sodium dodecyl sulfate (SDS) and poly(ethylene glycol)-diacrylate (PEGDA). Then, concentrated nanoemulsions (up to 60% oil volume fraction) are prepared through continuous phase evaporation at two different rates. The effect of volume fraction and continuous phase evaporation rate on nanoemulsions gelation are studied in this work by estimating interdroplet interactions and measuring the rheological properties.
