Divinylbenzene-Cinnamic Acid Porous Copolymers for Efficient Removal of Methylene Blue from Water

The removal of persistent organic pollutants from water remains a major challenge in environmental protection, driving the development of advanced sorption materials. In this work, porous copolymers based on divinylbenzene (DVB) and trans-cinnamic acid (CA) were synthesized via suspension polymerization and evaluated as sorbents for methylene blue (MB) removal from aqueous solutions. The effect of monomers composition on the structural and adsorption properties of the prepared materials was systematically investigated. FTIR spectroscopy, N₂ sorption experiments, differential scanning calorimetry (DSC), and optical microscopy were used to characterize properties of the polymeric products and to confirm the assumed course of the synthesis. Sorption properties were evaluated by means of a solid phase extraction method (SPE), which demonstrated effective adsorption of MB. The sorption performance strongly depended on copolymer composition. The sorption capacities towards MB were in the range of 40-55 mg g^-1. The highest effectiveness of MB removal had DVB-CA 1:1.5-55 mg g^-1 for which breakthrough took place at the solution volume of 10 L. It had a specific surface area 444 m²g^-1 and very uniform pores with a width of 3-5 nm. Desorption studies indicated partial reversibility of adsorption, suggesting potential capability of regeneration.