Search

[Display omitted] • A charge balanced adsorbent is fabricated for uranium extraction from seawater. • The adsorbent can resistant both biofouling and abiotic fouling. • The uranium extraction capacity is highly enhanced. • The uranium adsorption ability and anti-adhesive ability are highly reusable. The extraction of uranium from seawater is vital to meet the increase demands of uranium resource for the nuclear energy industry, while it is severe hazarded by the marine fouling, including both the biofouling and abiotic fouling. Previous reports only focused on the control of biofouling and rare attention is paid to the abiotic fouling. However, the abiotic fouling is the fundamental of the biofouling. Herein, a charged balanced hydrogel adsorbent is fabricated by introducing the charge-positive tetraethylenepentamine (TEPA) into the charge-negative polyacrylamidoxime (PAO). The fabricated PAO-CB hydrogel membrane shows high anti-adhesive ability to the marine fouling, including both the biofouling and abiotic fouling, which is due to the decrease of the charge attraction between the adsorbent and the charged contaminants. Benefitting from the reduce of marine fouling, the PAO-CB hydrogel membrane shows a high uranium extraction capacity of 8.59 mg g−1, which is higher than that of PAO hydrogel membrane by 44.59%. The finding of this study indicates that the construction of charge balanced adsorbent would be an effective strategy to control the complicated marine fouling during uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • A charge balanced adsorbent is fabricated for uranium extraction from seawater. • The adsorbent can resistant both biofouling and abiotic fouling. • The uranium extraction capacity is highly enhanced. • The uranium adsorption ability and anti-adhesive ability are highly reusable. The extraction of uranium from seawater is vital to meet the increase demands of uranium resource for the nuclear energy industry, while it is severe hazarded by the marine fouling, including both the biofouling and abiotic fouling. Previous reports only focused on the control of biofouling and rare attention is paid to the abiotic fouling. However, the abiotic fouling is the fundamental of the biofouling. Herein, a charged balanced hydrogel adsorbent is fabricated by introducing the charge-positive tetraethylenepentamine (TEPA) into the charge-negative polyacrylamidoxime (PAO). The fabricated PAO-CB hydrogel membrane shows high anti-adhesive ability to the marine fouling, including both the biofouling and abiotic fouling, which is due to the decrease of the charge attraction between the adsorbent and the charged contaminants. Benefitting from the reduce of marine fouling, the PAO-CB hydrogel membrane shows a high uranium extraction capacity of 8.59 mg g−1, which is higher than that of PAO hydrogel membrane by 44.59%. The finding of this study indicates that the construction of charge balanced adsorbent would be an effective strategy to control the complicated marine fouling during uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

• Poly(amidoxime)/Polyzwitterionic adsorbent is fabricated for uranium extraction. • The adsorbent can be easily prepared by free-radical polymerization. • The adsorbent shows high salt shrinkage resistance. • The adsorbent exhibits excellent antibacterial activity. • A high uranium extraction capacity of 6.26 mg g−1 in natural seawater. Effective uranium extraction from seawater can contribute greatly for meeting the needs of low carbon energy. Extensive studies have been conducted on polyamidoxime-based (PAO-based) adsorbents for their exceptional uranium adsorption capabilities. However, the salt-shrinkage effect severely hinders the extraction of uranium from seawater using traditional PAO-based adsorbents. This study synthesizes a novel semi-interpenetrating polymer network hydrogel, designated as PAO/PMPC-SH, using a free-radical polymerization approach utilizing PAO and zwitterionic poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC). The incorporation of the PMPC component endows the adsorbent with exceptional resistance to salt shrinkage owing to the antipolyelectrolyte effect. This characteristic facilitates the diffusion of uranyl ions within PAO/PMPC-SH, even in a high-salt environment with a salt concentration as high as 25 wt%, thereby exposing the uranium binding sites in the adsorbent. Moreover, PAO/PMPC-SH exhibits exceptional antibacterial activity. After 28 days of test in natural seawater, PAO/PMPC-SH demonstrates a high uranium extraction capacity of 6.26 mg g−1, representing only a 9.14 % decrease compared with the capacity of adsorbing in marine microorganism-removed natural seawater. Overall, the notable performance of PAO/PMPC-SH in uranium extraction highlights its potential as a highly effective adsorbent for uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • A morph-genetic biomimetic concept for fabricating zwitterionic hydrogels was proposed. • Macro-porous structures inside CTDPH matrix avoid the formation of salt crystallization. • The seawater evaporating rate of CTDPH increases to 3.11 kg m-2h−1 under 1-sun irradiation. • The CTDPH maintains 91.6% of its original solar evaporation rate even after 10 cycles. Huge seawater resources are of utmost importance in addressing the increasing and severe water shortage worldwide. However, high-efficiently and sustainably extracting fresh water from seawater through solar evaporation remains a challenging task. Herein, we propose a novel approach based on the morph-genetic biomimetic concept, utilizing a cuttlebone-templated directional porous hydrogel (CTDPH). By etching away the cuttlebone (CaCO 3) in the hydrogel network, we have developed a zwitterionic material that exhibits high-efficiency photo-thermal conversion, resistance to salt deposition, and super hydrophilicity, enabling high-efficiency solar evaporation. The resultant CTDPH demonstrates a high level of photo-thermal conversion efficiency, thanks to the incorporation of MXene (Ti 3 C 2 T x) 2D nanosheets. By introducing polyzwitterions into the hydrogel matrix, the CTDPH achieves superhydrophilicity, greatly enhancing the transport of seawater. More importantly, the CTDPH possesses a penetrating oriented macro-porous structure, enabling rapid seawater transportation while effectively preventing salt crystallization. This prevents salt deposition on the surface of the hydrogel even during continuous 12-hour 1.0 sun irradiation. As a result, compared with the MXene-free gels and cuttlebone-reserved gels, this CTDPH can largely increase the seawater evaporating rate from 0.73 or 1.75 to 3.11 kg m-2h−1 under 1.0 sun irradiation. Furthermore, even after undergoing 10 cycles of seawater evaporation, the CTDPH still maintains 91.6% of its original solar evaporation rate (2.85 kg m-2h−1). The CTDPH emerges as a promising contender, offering both high efficiency and sustainability for solar evaporation from seawater, while simultaneously paving the way for innovative approaches to explore other materials and systems in the realm of solar evaporation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mussel-inspired photothermal PAO hydrogel adsorbents were successfully fabricated. • PDA contributes to excellent hydrophilicity and photothermal conversion capacity. • Light irradiation yields the high uranium sorption capacity of 12.67 mg-U/g-Ads. • Excellent adsorption selectivity towards U(VI) over V(V) can be obtained. • Fe3+ coordination endows with excellent tensile strength and self-recovery ability. The efficient development of selective adsorbents for uranium extraction from seawater is necessary for their potential application in nuclear power generation. The amidoxime-based adsorbents have been recognized as the potential candidates, whereas they still suffer from a much higher affinity towards V(V) present in the seawater over U(VI), leading to the extremely limited commercial use. In this work, we develop a novel mussel-inspired photothermal polyamidoxime (PAO) hydrogel adsorbent, in which polydopamine (PDA) chains are linked to PAO (PDA-PAO) via Michael addition. Dual-crosslinked Fe@PDA-PAO hydrogel structure is constructed by noncovalent bonds between the catechol of PDA chains (e.g. π-π stacking and hydrogen bonds) as well as ionic coordination of Fe3+. PDA contributes to the improved hydrophilicity and high photothermal conversion efficiency. As a result, after immersing in real seawater for 6 weeks, light-irradiated Fe@PDA-PAO hydrogel delivers high uranium sorption capacity (12.67 mg-U/g-Ads) together with high U/V mass ratios (1.17), which are superior to currently available hydrogel adsorbents. Meanwhile, Fe3+ coordination endows Fe@PDA-PAO hydrogel with excellent tensile strength and self-recovery ability, which are of great significance to withstand the harsh conditions of ocean environment for practical applications. The results presented here reveal that Fe@PDA-PAO hydrogel holds tremendous potential for practical applications in the uranium-selective extraction from seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • KIST hydrogel shows shortest equilibrium adsorption time among existed adsorbents. • High uranium extraction capacity of 1.18 mg g−1 is achieved in natural seawater. • KIST hydrogel shows high antibiofouling activity against marine microorganisms. • KIST hydrogel exhibits high mechanical properties. Highly efficient extraction of uranium from seawater is vital for meeting the growth demands of uranium resources for the development of nuclear energy industry. However, currently available uranium adsorbents encounter multiple challenges, including the ultralong extraction period, severe marine biofouling, and violent impact of ocean motions. Targeting on these challenges and inspiring by the high tolerance of kelp to marine biofouling and motions, a kelp inspired super-toughness (KIST) bio-hydrogel is fabricated for uranium extraction from seawater. The hydrogel KIST is prepared by compositing the biofriendly and low-cost bacterial cell debris with polyvinyl alcohol, making the KIST hydrogel possesses high environment friendly. Attributing to the fast uranium adsorption rate of the bacterial cell debris, the KIST hydrogel realizes a uranium extraction capacity of 1.18 mg g−1 in biofouling-containing natural seawater with an ultrafast equilibrium adsorption time of 28 h, which is the shortest among all available uranium adsorbents in natural seawater. The antimicrobial activity of the bacterial cell debris empowers KIST hydrogel with as high as 99.21% inhibition rate to the growth of a broad range marine biofouling microorganisms, including the marine bacteria and marine algae. The KIST hydrogel also possesses outstanding tensile ability, flexibility, and rheological property, endowing the hydrogel with high resistance to the ocean current. Taking into consideration these advantages, the KIST hydrogel would be a promising adsorbent for practical uranium extraction. [ABSTRACT FROM AUTHOR]