Zhou Min, Liu Zhenglin, Lu Dandan, Wang Jiajun, Chen Zili, Qiu Yunren
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Polymers (Basel). 2025 May 14;17(10):1341. doi: 10.3390/polym17101341.
Due to the similar physicochemical properties of rare earth ions, their separation presents significant challenges. In this study, acidic phosphonic chitosan (aPCS) was prepared by modifying chitosan with phosphite and formaldehyde for improving the water solubility and complexing ability of rare earth ions in acidic aqueous solutions. DFT calculations revealed that its phosphonic groups serve as preferred reaction sites, forming stable bidentate complexes with rare earth cations. The complexation abilities of aPCS and phosphorylated chitosan (PCS) for La(III) were compared at various pHs by complexation-ultrafiltration. The results showed that aPCS achieved a 97% rejection for La(III), while 70% for PCS at pH 5 and P/RE 10. Furthermore, aPCS maintained higher rejection than PCS at pH of 3 to 7. In conclusion, aPCS demonstrates excellent potential for the selective extraction and purification of rare earth ions.
由于稀土离子具有相似的物理化学性质，它们的分离面临着重大挑战。在本研究中，通过用亚磷酸酯和甲醛对壳聚糖进行改性制备了酸性膦化壳聚糖（aPCS），以提高稀土离子在酸性水溶液中的水溶性和络合能力。密度泛函理论（DFT）计算表明，其膦酸基团作为优先反应位点，与稀土阳离子形成稳定的双齿络合物。通过络合超滤比较了aPCS和磷酸化壳聚糖（PCS）在不同pH值下对La(III)的络合能力。结果表明，在pH 5和P/RE为10时，aPCS对La(III)的截留率达到97%，而PCS为70%。此外，在pH 3至7时，aPCS的截留率高于PCS。总之，aPCS在稀土离子的选择性萃取和纯化方面显示出优异的潜力。
