Synthesis and applications of phase-change recyclable microgels with ultrafast adsorbing performance towards U(Ⅵ)

Rapid treatment of uranium in seawater is an important topic that needs to be addressed urgently. Microgel materials are considered ideal for rapid adsorption due to their ability to absorb water quickly. In a seawater environment, amidoxime materials exhibit superior selectivity for uranium enrichment. However, the modification of amidoxime groups onto microgels must be conducted in organic solvents. These solvents are unable to sufficiently swell and dissolve common microgels, leading to shrinkage that nearly blocks all modification reactions. Here, the thermo-responsive N'N -diethylpropionamide (DEA) was chose as the skeleton monomer to synthesize microgels, which showed both good hydrophilicity and oleophilicity properties The difference between the particle size of synthesized microgels in water and ethanol was not obvious. Due to the integration of microgels and kairamidoxime materials, the AO-Microgels demonstrate a maximum adsorption capacity of 79.29% within just 3 min. Additionally, their selective adsorption capacity for uranium in simulated seawater is remarkable. Furthermore, it simplifies the recycling process because of its intelligent temperature responsiveness.