Effect of intercalated aromatic sulfonates on uptake of aromatic compounds from aqueous solutions by modified Mg–Al layered double hydroxide

In this study, we utilized Mg–Al layered double hydroxide (Mg–Al LDH) modified by intercalation with three aromatic sulfonates—2,7-naphthalene disulfonate (2,7-NDS2−), benzenesulfonate (BS−), and benzenedisulfonate (BDS2−)—for the uptake of two aromatics—1,3-dinitrobenzene (DNB) and anisole (AS)—from aqueous solution and determined the effect of the aromatic sulfonates on the uptake of these aromatics. We found that the electron-rich aromatic ring of the intercalated aromatic sulfonates such as 2,7-NDS2− undergoes strong π–π stacking interactions with the electron-poorer benzene ring of DNB in aqueous solution, and these interactions result in a higher uptake of DNB by the modified Mg–Al LDHs. In contrast, the electron-poor aromatic ring of the aromatic sulfonates such as BDS2− undergoes weak π–π stacking interactions with the electron-poorer benzene ring of DNB, and these interactions result in a lower uptake of DNB by the modified Mg–Al LDHs.