A novel polymeric adsorbent by a self-doped manner: synthesis, characterization, and adsorption performance to phenol from aqueous solution

Abstract

The organic–inorganic self-doped poly (vinyltrimethoxy silane-ethylene glycol dimethacrylate) (VE resin) was synthesized by solution polymerization, hydrolysis and dehydration condensation. In this method, ethylene glycol dimethacrylate (EGDMA) was used as cross-linked reagent to form a three-dimensional network structure. Then, the system was prepared by radical polymerization in the presence of the hydrolysis of –OCH3 and the dehydration condensation of Si–OH. The maximum adsorption capacity 75.68 mg g−1 was achieved when pH was 6, the contact time 60 min, the adsorbent dose 0.1 g, the initial concentration 3000 mg L−1 and the temperature 293 K. The adsorption kinetics followed the pseudo-second-order kinetic model, and the intra-particle diffusion was but not the only rate-limiting step. Adsorption isotherms of phenol were linearly correlated and found to be well represented by the Freundlich model. Thermodynamic parameters such as changes in the enthalpy (ΔH), free energy (ΔG) and entropy (ΔS) indicated that the adsorption process of phenol on VE resin were physical and exothermic. After four regeneration recycles, the adsorption capacity of VE resin remained at 95.04 % of the initial value, which illustrated that it possessed good regeneration capacity.