Synthesis and characterization of polymer microspheres and its application for phenol adsorption

This paper reports synthesis of the poly(ethylene glycol dimethacrylate-n-vinyl imidazole) ([poly(EGDMA-VIM)]) microspheres by suspension polymerization for the removal of phenol from an aqueous solution. The synthesized [poly(EGDMA-VIM)] microspheres were characterized by various analysis techniques. The [poly(EGDMA-VIM)] microspheres possessed a high specific surface area (304.4 m2 g(-1)). It was found that the pseudo-second-order kinetic and Freundlich isotherm models could well define the phenol adsorption process. The maximum capacity of the [poly(EGDMA- VIM)] microspheres was calculated to be 34.7441 mg g(-1) at 298 K and natural pH from Langmuir isotherm. The adsorption thermodynamics revealed that the adsorption of phenol was an exothermic and spontaneous process. The [poly(EGDMA-VIM)] microspheres were easily regenerated by using a 0.01 M NaOH solution, and were repeatedly used for at least 5 cycles without losing the adsorption capacity. The experimental results suggest that the [poly(EGDMA-VIM)] microspheres can be implemented as a promising adsorbent for phenol removal from wastewater.