Preparation and adsorption performance of hypercrosslinked polymeric adsorbents modified by phenolic hydroxyl group

The hypercrosslinked polystyrene adsorbents of LY-4 and LY-5 were prepared By Friedel-Crafts post-crosslinking reaction with phenol and naphtho. The physical properties of absorbents showed that both phenolic hydroxyl group content and BET surface area of LM-5 are higher than LM-4. Accordingto the adsorption experiment in aqueous solution, the adsorption capacity of aniline onto LM-5 is bigger than that of phenol. The adsorption enthalpies of ΔH for adsorption of phenol (aniline) onto LM-5 are all negative and their absolute values are lower than 40 kJ/mol, which indicate that the adsorption is exothermic process and the physical adsorption is dominant in the adsorption process. Both The Gibbs free energy change of ΔG and adsorption entropy change ΔS of the adsorption are also less than zero which demonstrates that the adsorption is a spontaneous process. The absolute values of ΔH, ΔG and ΔS for adsorption of aniline onto LM-5 is bigger than that of phenol.