Preparation of poly(divinylbenzene-co-methyl acrylate) adsorbent with tunable surface hydrophilicity for atrazine removal

To efficiently remove atrazine, it is crucial to facilitate synergistic adsorption effect between aromatic structure and hydrophilic adsorption sites through tuning surface hydrophilicity. Herein, we reported a polymer adsorbent which was synthesized by copolymerizing divinylbenzene (DVB) and methyl acrylate (MA) with different monomer ratio, and subsequently hydrolyzing the copolymer to obtain carboxyl group on its surface. The surface hydrophilicity could be easily adjusted by changing the ratio of monomer and the optimal feeding ratio was 4:1 (VDVB:VMA) in terms of porosity (specific surface area 712.92 m2/g) and hydrophilicity regarding atrazine adsorption. The adsorption process followed the Langmuir isotherm with a maximum adsorption capacity of 75.75 mg/g. The mixed surface reaction and film diffusion model revealed that the adsorption procedure is dramatically controlled by film diffusion. Atrazine molecules diffusive and bound with porous adsorbent via strong hydrogen bonding between N (triazine and amine) and carboxyl groups introduced by copolymerization. Furthermore, high porosity caused by aromatic crosslinked network provided sufficient adsorption sites through π-stacking interaction. This work not only supplies a highly efficient adsorbent for atrazine removal but also enables a platform for preparation of polymers with tunable porosity and surface hydrophilicity. Mixed surface reaction and film diffusion model reveals that hydrophilicity of carboxyl group introduced by copolymerization dramatically improve atrazine diffusion, meanwhile, synergistic effect between the dominated aromatic π-stacking and hydrogen bond plays an important role in the adsorption process. [Display omitted]