Tunable Swelling Behaviors of Temperature-Responsive UO 2 2+ -Imprinted Polymeric Hydrogel Tailored for Highly Selective Uranium Extraction

作者：Shaobo Ren, Zhiming Li, Ju Lv, Pengfei Han, Xinyue Zhang, Lang Pan, Ying You, Xueqiong Yin, Xingqing Xiao · 发表于：ACS Applied Polymer Materials · 年份：2025 · DOI：10.1021/acsapm.5c00210 · 被引用次数：4 · 研究领域：Radioactive element chemistry and processing、Analytical chemistry methods development、Covalent Organic Framework Applications

The ion imprinting technique was applied in this work to prepare a thermosensitive biomass-based polymeric hydrogel, termed UITB, which exhibits unique temperature-dependent swelling behavior: it shrinks at high temperatures but swells at low temperatures. The reversible swelling property enables the UITB polymer gel to capture and release UO 2 2+ ions by adjusting the temperature within a moderate range of 20°C–45°C. A high adsorption selectivity of UITB for the target UO 2 2+ ions was observed in the presence of decoy metal ions. Rinsing with pure water for the elution of the absorbed UO 2 2+ greatly extends the lifetime of the polymer gel. Subsequently, various thermodynamic models were used to theoretically study the adsorption equilibrium and kinetics of UITB. A monolayer adsorption was identified, with the adsorption dynamics being controlled by both the diffusion process and electron transfer. To explore the molecular mechanism of UO 2 2+ adsorption at the microscale level, atomistic molecular dynamics simulations were performed to investigate the adsorption behavior of UO 2 2+ in two computationally modeled hydrogel network units of different pore sizes. Analysis of the energies showed that the negative intermolecular ELE+EGB energy is responsible for the adsorption and desorption of UO 2 2+ on the polymer gel, while the positive intermolecular VDW energy indicates that the UO 2 2+ ions are prevented from being absorbed anywhere except within the cavities. Finally, te...