Hydroquinone-modified hyper-crosslinked polymer and its adsorption of aniline

The nucleophilic substitution and Friedel-Crafts alkylation were performed for chloromethylated polystyrene, and the hydroquinone-modified hyper-crosslinked polymer, namely, PS-KHQ-HCP, was prepared accordingly. The nucleophilic substitution offered plentiful oxygen for PS-KHQ-HCP and the Friedel-Crafts alkylation provided PS-KHQ-HCP with hyper-crosslinking frameworks. As a result, PS-KHQ-HCP possessed abundant oxygen (13.04 wt.%) and high Brunauer-Emmett-Teller surface area (437 m2/g). The adsorption experiments indicated that PS-KHQ-HCP displayed efficient adsorption to aniline with a maximum adsorption capacity of 166.8 mg/g at the original solution pH of 7.8, and the adsorption enthalpy (ΔH: -18.62 kJ/mol) and adsorption entropy (ΔS: -62.87 J/(mol·K)) were predicted to be negative. The kinetic curve displayed that it was sufficient for the adsorption to reach equilibrium within 120 min. The adsorption mechanism revealed that the introduced oxygen was beneficial for the adsorption because of the possible hydrogen bonding and acid-base interaction.