Magnetic polyacrylonitrile/ZIF-8/Fe3O4 nanocomposite bead as an efficient iodine adsorbent and antibacterial agent

Abstract

The efficient adsorption of radioactive iodine (129I and 131I) as nuclear waste is of great importance. Polymer nanocomposites consist of metal–organic frameworks (MOFs) developing for various pollutions sorption and separation have attracted much attention. This study reports the fabrication of magnetic polyacrylonitrile (PAN)/zeolitic imidazolate frameworks (ZIF-8) nanocomposites, PAN/ZIF-8(x%)/Fe3O4, x = 30 and 50, as iodine capture adsorbents. The PAN/ZIF-8(x%)/Fe3O4 nanocomposite beads were fabricated via the phase inversion method, and their potential for iodine capture and separation in solution and vapor was investigated through UV–vis and weighing methods, respectively. Also, antibacterial activity of the as-prepared beads was assessed against E. coil and S. aureus. The as-fabricated compounds were studied by various techniques such as Fourier-transform infrared, X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy mapping, transmission electron microscope, N2 adsorption isotherm, and vibrating sample magnetometer. The iodine capture results showed that the efficiency of nanocomposites is remarkably higher than the pure PAN beads. Additionally, the as-prepared nanocomposite adsorbents displayed higher capture capacities for iodine vapor (1524–4345 mg·g−1) than iodine solution (187–295 mg·g−1). The as-obtained magnetic nanocomposites can be successfully separated from polluted media by simple filtration or an external magnet, regenerated through washing with ethanol, and reused. Fast capturing, high sorption capacity, rapid separation, and good reusability make the PAN/ZIF-8(x%)/Fe3O4 nanocomposites highly effective adsorbents for the separation of iodine from wastewater. Additionally, PAN/ZIF-8(50%)/Fe3O4 bead can be considered as a potential new antibacterial agent for water and wastewater treatment.