Tertiary amino groups modified macroporous crosslinked poly(styrene-co-divinylbenzene) and its oxidized adsorbent: Synthesis, characterization, and adsorption behavior

Macroporous crosslinked poly(p-vinylphenyltrimethylamine) (PVPTA) and its oxidized adsorbent (OPVPTA) were synthesized and their adsorption behaviors for phenol were comparatively studied in hexane as well as in aqueous solution. The results indicated that the adsorption was enhanced after PVPTA being oxidized, and the adsorption capacity of phenol onto OPVPTA was higher than that onto the commercial Amberlite XAD-4 resin in aqueous solution. The adsorption isotherms in hexane were fitted to Langmuir and Freundlich models, and it was found that the Freundlich model was suitable for characterizing the adsorption, whereas the correlation of the equilibrium adsorption in aqueous solution was linear. The adsorption was very sensitive to the solution pH and the optimum condition was at about the neutral solution. The adsorption thermodynamic parameters were calculated and it revealed that the adsorption was an exothermic, spontaneous, and more ordered process. Investigation of the adsorption mechanism suggested that hydrogen bonding was the primary driving force for the adsorption. (C) 2008 Elsevier B.V. All rights reserved.