Design of high-performance adsorption cross-linked organic functional polymers towards tricyclic antidepressants using computational simulation

Computational simulations of eighteen functional monomers to produce cross-linked polymers containing high adsorption efficiency to tricyclic antidepressants [amitriptyline (AMT), clomipramine (CLO), doxepin (DOX), imipramine (IMI) and nortriptyline (NOR)] in aqueous medium were evaluated and selected to polymers synthesis. Among them, acrylic acid (AA) and methacrylic acid (MA) were chosen to synthesize the poly(AA-co-EGDMA) and poly(MA-co-EGDMA) adsorbents due to their contrasting calculated interaction energies and to their similar chemical structures. The polymers were characterized by dynamic light scattering (DLS), elemental analysis, swelling effect and textural data. Higher tricyclic antidepressants adsorptions were obtained at pH 7.0 to both polymers, with superior results to poly(AA-co-EGDMA). From the adsorption kinetics the pseudo-second order, Elovich and intraparticle diffusion models showed good adjustments on experimental data of both polymers. The adsorptive predicted by the pseudo-second order model for the poly(AA-co-EGDMA) were 537, 480, 441, 522, 542 mu mol g(-1) to AMT, CLO, DOX, IMI and NOR, respectively, while to poly(MA-co-EGDMA) were 243, 120, 226, 205 and 178 mu mol g(-1). By the thermodynamic parameters, the adsorption process was characterized as endothermic and spontaneous, accompanied by an increase of disorder at the solid-solution interface. The higher adsorption capacity of poly(AA-co-EGDMA) to the antidepressants than to the poly(MA-co-EGDMA) demonstrates agreement with the interaction predicted by the computational simulation, showing its efficiency on predict the best functional monomer to synthesize polymeric adsorbents.