Selective Absorption of Aromatic Compounds by Syndiotactic Polystyrene Aerogels

Experimental measurements are combined with mathematical modeling in order to investigate the selective absorption of aromatic molecules (benzene, phenol, and toluene) from aqueous solutions by syndiotactic polystyrene (sPS) monolithic aerogels. The experimental results with aqueous solutions of a single aromatic compound show high absorption efficiency for the non-polar compounds (toluene: approximate to 94%; benzene: approximate to 77%), whereas phenol (polar compound) is poorly absorbed with an efficiency of about 12%. Furthermore, phenol is no way removed from aqueous phase in presence of NaCl while the water salinity do not affect the absorption efficiency toward toluene and benzene in ternary aqueous solution, evidencing also that toluene is preferentially uptaken by aerogels with a superior kinetic and higher diffusivity constant with respect to benzene. The results obtained in this work underline that sPS aerogels can be interesting materials to selectively recover non-polar compounds from seawater by means of an absorption process.