Porous Microparticle Preparation via Tuning Electrostatic Breakup Characteristics of a Non-Newtonian Fluid for High-Performance Uranium Extraction

Although polyamidoxime (PAO)-based materials have been acknowledged as one of the most promising adsorbents for commercial-scale uranium extraction, preparing materials with controllable size, high-performance uranium extraction, and effortless recovery is still challenging. The current study explores the potential of combining the electrohydrodynamic atomization (EHDA) technique with high-performance uranium extraction, where composite microparticles (CMPs) were facilely prepared via the EHDA technique, with the particle size being precisely controlled. The precursor is made of an environmentally friendly aqueous solution of PAO and sodium alginate (SA) at a certain ratio. Droplet breakup mechanism of the PAO/SA precursor under a nonuniform electric field was studied, which would result in PAO/SA CMPs with better controlled size. The produced CMPs were characterized to be a hollow structure, ranging from 100 to 2000 μm in size (long diameter), with interpenetrating nanopores being observed inside the particle shell. The equilibrium adsorption capacity increases gradually from ∼400 to ∼800 mg/g with decreasing particle size from 2200 to 120 μm. Hence, the uranium adsorption performance can be easily tuned to adapt to different application scenarios by altering the CMP size, which can be readily achieved via the EHDA technique. This work offers a novel route for generating high-performance uranium adsorbents with desired size and structure, in a highly efficient, facile, and low-cost way, showing great potential for industrial applications.