▎ 摘　　要

Simulations at multiple levels were performed to investigate the aqueous adsorption of phthalate esters (PAEs) on carbon nanoparticles and to find the competitive effect of a low molecular weight natural organic acid (benzoic acid) on the adsorption process. Six PAEs of varying alkyl side chain lengths and three carbon-based nanomaterials including a single-walled carbon nanotube (SWNT), double-walled carbon nanotube (DWNT), and graphene (G) were studied. Results showed that the adsorption energies calculated using density functional theory increase with increasing length of the PAE alkyl chain. G exhibits higher adsorption capacity for the PAEs than SWNT and DWNT. The absolute adsorption energies of these systems also display a positive linear correlation with the hydrophobicity of the PAE molecules. Molecular dynamics simulations indicate that the presence of neutral/anionic benzoic acid in water alleviates the PAE adsorption. Furthermore, anionic benzoic acid exerts more impact on the PAE adsorption than the neutral form.