A Simple and Rapid Spontaneous Emulsification System for Highly Stable Emulsions

It is of great importance to maintain the stability of emulsions in order to perform their functions. However, emulsions are usually thermodynamic unfavorable systems that require a large amount of energy to prepare and high concentration emulsifiers to maintain the stability. This study presents a simple, rapid emulsifying system that can prepare highly stable emulsions in a low-energy manner. The spontaneous formation of emulsion droplets is driven by the neutralization reaction between fatty acids and triethylamine. Moreover, the accumulation of the reaction products at the water-oil interfaces can stabilize the emulsion droplets. Compared with emulsions prepared by fatty acid triethylamine salts, the spontaneous emulsifying system exhibits a superior emulsifying effect and yields emulsions with improved stability. A combination of systematic interfacial measurements, viscoelastic characterization and molecular dynamics (MD) simulations is used to elucidate the mechanism of spontaneous emulsification and emulsion stabilization. This straightforward, rapid, and reaction-driven emulsification strategy offers a new approach to achieving spontaneous emulsification and provides a novel method of preparing stable emulsions.