Synthesis, properties and applications of new hybrid material based on native/magnetically modified sepiolite and chitosans

The study introduces novel hybrid materials containing native and magnetite-containing sepiolite (Sep, SepM respectively) and chitosans (Ch) of different molecular weights. The main objective of this work was to determine the properties of these materials, including the different types of stability (colloidal, gravitational and thermal) in systems containing sepiolite, in order to obtain effective, stable and easily producible hybrid materials with great potential for water and wastewater treatment. The following measurements and methods were performed to characterize the investigated system: low-temperature nitrogen adsorption–desorption, zeta potential analysis, UV–Vis, FT-IR, XRD, XRF, SEM-EDS, TGA, DSC and DTG. It was found that the complexes with high molecular weight chitosan exhibited the best stability of the systems. The same tendency was observed for the concentration dependence: the higher the chitosan concentration, the better the stabilization of the composites. Overall, this study shows that chitosan effectively improves the colloidal and gravitational stability of the composites. Due to its unique structure, the synthesized magnetic hybrid material has shown great advantages in the adsorptive removal of textile dyes such as anionic acid red 88 (AR88) and cationic methylene blue (MB) which can be easily removed from the dye solutions after its use using an external magnetic field.