Constructing amidoxime adsorption sites on the core-shell structured natural silk protein for uranium capture

Chen Huang; Lin Ma; Chengkai Mao; Peng Sun; Lu Xu; Haiyang Shao; Ranran Wang; Minghong Wu; Hongjuan Ma

doi:10.1016/j.ijbiomac.2024.131608

Constructing amidoxime adsorption sites on the core-shell structured natural silk protein for uranium capture

Int J Biol Macromol. 2024 Apr 14;267(Pt 2):131608. doi: 10.1016/j.ijbiomac.2024.131608. Online ahead of print.

Authors

Chen Huang¹, Lin Ma², Chengkai Mao³, Peng Sun³, Lu Xu², Haiyang Shao³, Ranran Wang⁴, Minghong Wu⁵, Hongjuan Ma⁶

Affiliations

¹ Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
² Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
³ Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
⁴ School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
⁵ Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China. Electronic address: mhwu@shu.edu.cn.
⁶ Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China. Electronic address: hongjuanma@shu.edu.cn.

PMID: 38621558
DOI: 10.1016/j.ijbiomac.2024.131608

Abstract

Amidoxime-based fiber adsorbents hold significant promise for uranium extraction. However, a notable issue is that these adsorbents primarily originate from synthetic polymer materials, which, aside from providing good mechanical support, have no other functions. In recent study, we shifted our focus to silk fiber (SF), a natural protein fiber known for its unique core-shell structure and rich amino acids. The shell layer, due to its abundant functional groups, makes it easily modifiable, while the core layer provides excellent mechanical strength. Leveraging these inherent properties, an amidoxime-based fiber adsorbent was developed. This adsorbent utilizes amino and carboxyl groups for enhanced performance synergistically. This method involves establishing uranium affinity sites on the outer sericin layer of SF via chemical initiation of graft polymerization (CIGP) and amidoximation (SF-g-PAO). The water absorption ratio of SF-g-PAO is as high as 601.16 % (DG = 97.17 %). Besides, SF-g-PAO demonstrates an exceptional adsorption capacity of 15.69 mg/g in simulated seawater, achieving a remarkable removal rate of uranyl ions at 95.06 %. It can withstand a minimum of five adsorption-elution cycles. Over a 4-week period in natural seawater, SF-g-PAO displayed an adsorption capacity of 4.95 mg/g. Furthermore, SF-g-PAO also exhibits impressive uranium removal efficiency in real nuclear wastewater, with a removal rate of 63 % in just 15 min and a final removal rate of 90 %. It is hoped that this SF-g-PAO, prepared through this straightforward method and characterized by the synergistic action of amino and carboxyl groups, can offer innovative insights into the development of uranium extraction adsorbents.

Keywords: Amidoxime; Amino acids; CIGP; Core-shell structure; Silk.