Advanced Amidoximated Polyethylene Nanofibrous Membranes for Practical Uranium Extraction from Seawater

Abstract

As the key material of the adsorption method used for practical uranium extraction from seawater, the adsorbent should have a high uranium adsorption capacity and long service life. Polyethylene nanofibrous membranes (PENFMs) using a one-step grafting strategy to prepare scalable membrane adsorbents are reported with supreme uranium uptake capacity and long service life. A series of amidoximated polyethylene nanofibrous membrane (called amidoximated membrane or AM) adsorbent materials with different degrees of grafting (DGs) are modified by one-step radiation-induced graft polymerization (RIGP) of acrylonitrile (AN) and acrylic acid (AA) and an amidoximation reaction. The AM adsorbents prepared from the PENFM show outstanding hydrophilicity, good adsorption capacity, and excellent affinity for uranium. The highest uranium uptake capacity of AM adsorbents is 115.32 mg/g in simulated seawater for 24 h and 6.03 mg/g in natural seawater for 10 weeks. The AM adsorbents are reusable for more than 10 cycles of continuous adsorption–desorption–regeneration tests, showing the long service life. In addition, the AM adsorbent adsorption results in natural seawater indicate that only prolonging time to pursue high adsorption capacity is not conducive to the acquisition of benefits. The AM adsorbents have broad potential application in the industrialization of uranium extraction from seawater by choosing the best adsorption efficiency to achieve high adsorption amount.

Zwitterion Functionalized Graphene Oxide/Polyacrylamide/Polyacrylic Acid Hydrogels with Photothermal Conversion and Antibacterial Properties for Highly Efficient Uranium Extraction from Seawater

“…[38,39] As per Figure 8b,e as well as Table S5 (Supporting Information), the peak of -NH 2 shifted from 401.18 to 401.38 eV, whereas that of -NH-changed from 399.18 to 399.38 eV, suggesting that the adsorption of U(VI) on PAGM-1 depends on-NH 2 and -NH-. [40,41] Furthermore, in the XPS spectrum of O 1s (Figure 8c,f as well as Table S5, Supporting Information), the binding energy of the oxygen-containing functional groups after the U(VI) adsorption shifted to a higher value. For example, COO − shifted from 530.78 to 530.88 eV, CO shifted from 531.68 to 531.98 eV, and C = O shifted from 532.78 to 532.88 eV.…”

Engineered Sorbents for Selective Uranium Sequestration from Seawater

“…80 Yu et al reported a novel one-step grafting approach to produce an expandable membrane-based sorbent to enhance the U recovery from both the simulated and natural seawater. 81 An array of amidoximated (AM) polyethylene nanofibrous membranes (PENFMs) were fabricated through one-step radiation-induced graft polymerization (RIGP) of acrylonitrile (AN) and acrylic acid (AA), followed by their amidoximation (Figure 3a). The synthesized membranes were thoroughly characterized by FT-IR, SEM, solid-state NMR, and XPS.…”

“…Graphene-based sorbents have gained increasing attention as promising materials for efficient and selective extraction of various ions from seawater. − A hydrogenated form of graphene exhibits an excellent thermal and chemical stability, as well as a high surface area, making it an attractive candidate for sorption applications. − Similar to the layered double hydroxides (LDHs), graphene-based sorbents possess interlayer spaces that allow efficient ion exchange, enabling the selective removal of contaminants from seawater. Recently, there has been a growing interest in using graphene oxide (GO) based materials/sorbents for the removal of U salts from seawater. , The GO-based nanocomposites (with large surface area) are highly functionalized materials and can be modified to incorporate different functional groups to expand their application.…”

“…(e) Proposed U sorption model of the cyclic imidedioxime group. Reproduced with permission from ref . Copyright 2022 American Chemical Society.…”

Alginate-based supermacroporous hydrogels fabricated by cryo-polymerization for uranium extraction from seawater

“…3 Nevertheless, UES is challenging due to the low uranium concentration (about 3.3 ppb). 4 Several extraction techniques, such as adsorption [5][6][7] flocculation, 8,9 membrane separation, [10][11][12] solvent extraction, 13,14 and ion exchange, 15,16 have been developed to extract uranium from seawater. Among the available methods, adsorption is deemed an efficient approach owing to its inherent cost-effectiveness, exceptional efficacy, and versatile potential for customization and operation.…”