改写：For the comprehensive understanding of the uranium uptake mechanism on the PAOPNIPAm DFT calculations were performed herein For the PNIPAm the uranyl energetically prefers to coordinate with N and

To gain a thorough understanding of the mechanism behind uranium uptake on PAO/PNIPAm, this study conducted DFT calculations. The results showed that, for PNIPAm, uranyl prefers to coordinate with N and O atoms on the acylamino, leading to the formation of a bidentate configuration with a binding energy of -25.79 kcal·mol-1 (as shown in Fig. 7a), which is lower than that of the monodentate configuration (as shown in Fig. S3). In order to further investigate the adsorption mechanism, the projected density of states (PDOS) of the bidentate configuration was examined (as shown in Fig. 7c). The U5f, 6d, and 7s states were found to be hydrides with O2p and N2s and 2p states, indicating chemical coordination between these atoms. Additionally, the independent gradient model (IGM) improvement method, specifically the IGM based on Hirshfeld partition of molecular density (IGMH), was utilized to explore the inter-fragment interaction among the weak interactions (as shown in Fig. 7b). The red, green, and blue spikes represent repulsive interaction (steric effect), vdW interaction, and H-bonding interaction, respectively. Notably, green sheet isosurfaces were observed in the adsorption model (as shown in Fig. 7b), suggesting that vdW interaction also plays a critical role in the adsorption configuration.