Synthesis of well-defined molecularly imprinted bulk polymers for the removal of azo dyes from water resources

Söylemez M. A., Okan M., Güven O., BARSBAY M.

Current Research in Green and Sustainable Chemistry, vol.4, 2021 (Scopus) identifier


© 2021 The AuthorsAzo dyes are employed quite commonly, although they can lead to the formation of carcinogenic aromatic amines. In this study, well-defined molecularly imprinted polymers (MIPs) with good recognition to 3 azo dyes (acid red 26, disperse blue 7 and direct blue 2b) were synthesized via radiation-induced reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization technique. The total adsorbed radiation dose was optimized as 1.18 ​kGy. Methacrylic acid and ethylene glycol dimethacrylate were used as functional monomer and crosslinking agent, respectively. Cumyl dithiobenzoate was employed as the RAFT agent. The synthesized MIPs were characterized in detail by various methods demonstrating their well-defined attitudes. The size of the free volume holes of MIPs differed upon the size of the template employed. The evaluation of the binding performances was investigated as a function of contact time and initial template concentration. The Langmuir isotherm best represented the adsorption behavior of the synthesized MIPs and the adsorption followed pseudo 2nd order kinetic model, referring that the rate determining step was chemisorption. The MIPs synthesized by RAFT method performed significantly higher in specific binding compared to those attained by conventional free-radical polymerization. This study presents pioneering results for the synthesis of well-defined azo-imprinted polymers using an environmentally-friendly method.