Development of Approaches for Designing and Preparing Magnetic Nanocomposites Based on Zeolite Beta and Magnetite Nanoparticles under Hydrothermal Conditions

Abstract

Nanocomposites based on zeolite Beta and magnetite nanoparticles (MNs) are obtained under hydrothermal conditions. Nanoparticles synthesized under various conditions and having different surface properties are added at the preparatory stage of a zeolite Beta gel that is then subjected to hydrothermal treatment at 140°C for 48 h. It is found that modifying the surface of the nanoparticles by a cationic polymer, polydiallyldimethylammonium chloride (PDDAC) makes it possible to significantly increase the amount of magnetite introduced into the zeolite structure (up to 40 wt % compared to 2–10 wt % for unmodified particles) and obtain zeolites with a magnetic core that contain nanoparticles within the zeolite structure. It is shown that doping the initial gels with MNs allows obtaining magnetically sensitive zeolites with particles of 100 to 200 nm, which are 200 nm smaller than the zeolite particles obtained under the same conditions without doping.