<p>The design and development of CO₂-responsive surfactants have become a hotspot in the field of smart materials, with significant progress achieved in recent years. Investigating emulsion structures at the molecular level is of great significance for gaining a deeper understanding of the mechanisms behind CO₂-responsive emulsification and demulsification. Emulsifiers composed of long-chain fatty acids and amine-based compounds offer advantages such as rapid responsiveness and low cost. In this work, molecular dynamics simulations were performed on a CO₂-responsive emulsification stabilized by capric acid and monoethanolamine. We focus on the molecular arrangement of surfactants at the droplet interface and their hydration effects. In the simulations, the concentration of surfactants was set to a very low level, which aligns with the experimental conditions where minimal amounts are used. Although the simulation results show that all oil molecules eventually coalesce into a single droplet, we have demonstrated through property characterization and vapor–liquid interface modeling that the ionized CA⁻-coated droplets exist as emulsion droplets. In contrast, after CA protonation, the simulation results reflect an oil–water separation state. The simulation results demonstrate an interesting phenomenon that the binding of anionic surfactants to ammonium salts was not as stable as expected, but the positively charged ammonium salts were constantly transferred between the individual anionic polar heads. The migration of surfactant on the droplet surface allows the entire droplet surface to maintain a sufficiently hydrated layer to stabilize the oil–water interface.</p>