Abstract: Using sodium cetyl m-xylene sulfonate as the surfactant and benzene,  naphthalene,  phenanthrene,  and pyrene as the aromatic hydrocarbon phases,  we used all-atom molecular dynamics simulation methods to study the effect of aromatic hydrocarbon phase changes on the properties of aromatic hydrocarbon/water interface, and analyzed interfacial thickness,  interfacial formation energy (IFE),  interfacial tension,  the radial distribution function and coordination number between surfactant molecules and aromatic hydrocarbon molecules,  and the diffusion coefficient of aromatic hydrocarbon phase and water phase. The results show that when the aromatic hydrocarbon phase is phenanthrene,  the interfacial thickness,  the interfacial formation energy  and the coordination number are the largest,  the interfacial tension and the diffusion coefficient between the aromatic hydrocarbon phase and the water phase are the smallest,  which has better solubilization and compatibility,  but the elution rate is the slowest.

Key words: aromatic hydrocarbon; , molecular simulation; , interface; , benzene ring number; , surfactant