Tuning the porosity of hypercrosslinked styrene-divinylbenzene copolymers for efficient adsorption of rifampicin from aqueous media

Abstract In this study, hypercrosslinked styrene-divinylbenzene copolymers (HCCPs) designated as HCCP-1DVB, HCCP-2DVB and HCCP-3DVB were obtained by post-crosslinking of styrene-divinylbenzene copolymers containing 1, 2 and 3 % of divinylbenzene by chloromethyl methyl ether via the Friedel-Crafts reaction. The chemical structure, porous and morphological characteristics of HCCPs were determined by FT-IR, low-temperature nitrogen adsorption-desorption method and SEM, respectively. The synthesized hypercrosslinked copolymers had high surface area values and different micro/mesoporous structures. It was found that mesopore volume increased with a decrease in divinylbenzene content in a copolymer. HCCP-1DVB had the largest mesopore volume (0.53 cm3/g), the highest adsorption capacity for rifampicin (qmax = 183.27 mg/g), and the highest rifampicin adsorption rate. The adsorption equilibrium and kinetic processes were well described by the Langmuir model and the pseudo-second-order model. The experimental data indicated that the removal efficiency of rifampicin reached 99.8 % at the dosage of HCCP-1DVB equal to 80 mg/10 mL. After 5 cycles of reuse, the adsorption capacity of HCCP-1DVB decreased only by 7 %, which indicates sufficient stability and reusability of this hypercrosslinked copolymer.