Carrageenan-grafted-poly(acrylamide) magnetic nanocomposite modified with graphene oxide for ciprofloxacin removal from polluted water

Abstract

The κ-carrageenan-grafted-poly(acrylamide)/Fe3O4-GO (κ-car-g-PAAm@Fe3O4-GO) adsorbent was attained in three stages, utilizing grafted poly(acrylamide) (PAAm) onto κ-carrageenan (κ-car) in Fe3O4 and graphene oxide (GO) presence. Various characteristic analyses were carried out to peruse the chemical properties, morphological features, thermal stability, magnetic behavior, and porosity of the prepared nanoadsorbent. According to the results obtained from the analyses, the prepared nanoadsorbent showed superparamagnetic behavior. It rendered a semicrystalline structure by Fe3O4 presence in the amorphous matrix of the κ-car-g-PAAm. The SEM images exhibit well dispersion of the Fe3O4 magnetic nanoparticles (MNPs) and lamellar GO sheets throughout the hydrogel context. Besides, along with the GO incorporation into the structure, the BET surface area (2.361 m2/g), pore volume (0.008 cm3/g), and pore size (137.49 nm) of the κ-car-g-PAAm@Fe3O4-GO nanoadsorbent were higher than κ-car-g-PAAm@Fe3O4. The maximum adsorption capacity (Qmax) at an ambient temperature for CPFX adsorption was 1146.467 mg/g. These adsorption experiments’ data were described by the Freundlich isotherm, and the pseudo-second-order explains the adsorption kinetics well. The retrievability of the prepared nanoadsorbent was studied and indicated that it could be isolated effectively and reused in three consecutive cycles without remarkable adsorption efficiency loss.