Novel Functionalized Cellulose Microspheres for Efficient Separation of Lithium Ion and Its Isotopes: Synthesis and Adsorption Performance

Molecules

Chenxi Xu¹  Maolin Zhai¹  Ichen Chen¹  Jing Peng¹  Dong Han¹  Siqi Liu¹ 

[1] Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;

关键词: cellulose microspheres;    crown ether;    radiation grafting;    adsorption;    separation of lithium isotopes;   

DOI  :  10.3390/molecules24152762

来源: DOAJ

【 摘 要 】

The adsorption of lithium ions(Li⁺) and the separation of lithium isotopes have attracted interests due to their important role in energy storage and nuclear energy, respectively. However, it is still challenging to separate the Li⁺ and its isotopes with high efficiency and selectivity. A novel cellulose-based microsphere containing crown ethers groups (named as MCM-g-AB15C5) was successfully synthesized by pre-irradiation-induced emulsion grafting of glycidyl methacrylate (GMA) and followed by the chemical reaction between the epoxy group of grafted polymer and 4′-aminobenzo-15-crown-5 (AB15C5). By using MCM-g-AB15C5 as adsorbent, the effects of solvent, metal ions, and adsorption temperature on the adsorption uptake of Li⁺ and separation factor of ⁶Li/⁷Li were investigated in detail. Solvent with low polarity, high adsorption temperature in acetonitrile could improve the uptake of Li⁺ and separation factor of lithium isotopes. The MCM-g-AB15C5 exhibited the strongest adsorption affinity to Li⁺ with a separation factor of 1.022 ± 0.002 for ⁶Li/⁷Li in acetonitrile. The adsorption isotherms in acetonitrile is fitted well with the Langmuir model with an ultrahigh adsorption capacity up to 12.9 mg·g⁻¹, indicating the unexpected complexation ratio of 1:2 between MCM-g-AB15C5 and Li⁺. The thermodynamics study confirmed the adsorption process is the endothermic, spontaneous, and chemisorption adsorption. As-prepared novel cellulose-based adsorbents are promising materials for the efficient and selective separation of Li⁺ and its isotopes.

【 授权许可】

Unknown