Multifunctional MOFs-polymer composite nanofibrous membrane for radioactive iodine aerosols efficient purification

The efficient purification of radioactive iodine aerosols is essential in developing nuclear energy. Using existing materials and processing processes, it is hard to efficiently purify iodine aerosols and iodine gas simultaneously. Membranes with excellent adsorption and filtration properties are suitable candidates for efficient purification. A simple one-step synthetic strategy developed from the electrospinning method fabricates a multifunctional composite nanofibrous membrane material (ZIF-8@PVP/PAN). The ZIF-8 crystals coated the fiber surface, and some were embedded into the PVP/PAN fiber without significantly changing the fiber diameter distribution. The ZIF-8@PVP/PAN membrane shows outstanding adsorption properties with a maximum adsorption capacity of 2898 mg/g for iodine gas and 456 mg/g for methyl iodide. In addition, at a face velocity of 5 cm/s, it exhibits excellent filtration efficiency of 99.91 % for PM 0.3 with a much lower pressure drop of 79 Pa. Combine the DFT theoretical calculations and characterization results, it can be considered that active adsorption sites provided by the PVP/PAN fiber framework and the loaded ZIF-8 enhanced the iodine adsorption together. The efficient filtration results from the synergistic effect of interception, adsorption, and electrostatic attraction. The ZIF-8@PVP/PAN composite membrane with excellent multifunctional performance and outstanding thermal and radiation stability provides a potential material for efficiently purifying iodine aerosols and iodine gas in reprocessing plants under practical working conditions.