Size effect of single-walled carbon nanotube on adsorption of perfluorooctanesulfonate

Perfluorooctanesulfonate (PFOS) is a typical persistent organic pollutant of more environmental concerns in the recent years. The adsorption of PFOS on the single-walled carbon nanotube (SWCNT) is studied with molecular dynamics (MD) simulation. The energy and conformational features are investigated via the statistical results from the MD trajectory. The size effect is observed from the adsorption of PFOS both on the inner and the outer surface. The non-bond interaction energy between PFOS and the inner surface of SWCNT is highly related to the diameter of nanotube. The conformation of PFOS is also changed by the sorbent surface. The PFOS molecule adsorbed on the outer surface is affected by the size of SWCNT more gently than that adsorbed in the nanotube. The aliphatic chain contributes most to the adsorption, as it locates more closely to the outer surface than the charged sulfuric group.