The emerging heterogeneous membranes show unprecedented superiority in harvesting the osmotic energy between ionic solutions of different salinity. However, the power densities are limited by the low ...interfacial transport efficiency caused by a mismatch of pore alignment and insufficient coupling between channels of different dimensions. Here we demonstrate the use of three-dimensional (3D) gel interface to achieve high-performance osmotic energy conversion through hybridizing polyelectrolyte hydrogel and aramid nanofiber membrane. The ionic diode effect of the heterogeneous membrane facilitates one-way ion diffusion, and the gel layer provides a charged 3D transport network, greatly enhancing the interfacial transport efficiency. When used for harvesting the osmotic energy from the mixing of sea and river water, the heterogeneous membrane outperforms the state-of-the-art membranes, to the best of our knowledge, with power densities of 5.06 W m
. The diversity of the polyelectrolyte and gel makes our strategy a potentially universal approach for osmotic energy conversion.
Ultra-selective and fast transport of K
are of significance for water desalination, energy conversion, and separation processes, but current bottleneck of achieving high-efficiency and exquisite ...transport is attributed to the competition from ions of similar dimensions and same valence through nanochannel communities. Here, inspired by biological KcsA channels, we report biomimetic charged porous subnanometer cages that enable ultra-selective K
transport. For nanometer to subnanometer scales, conically structured double-helix columns exhibit typical asymmetric transport behaviors and conduct rapid K
with a transport rate of 94.4 mmol m
h
, resulting in the K
/Li
and K
/Na
selectivity ratios of 363 and 31, respectively. Experiments and simulations indicate that these results stem from the synergistic effects of cation-π and electrostatic interactions, which impose a higher energy barrier for Li
and Na
and lead to selective K
transport. Our findings provide an effective methodology for creating in vitro biomimetic devices with high-performance K
ion sieving.
Ion transport in nanoconfinement exhibits significant features such as ionic rectification, ionic selectivity, and ionic gating properties, leading to the potential applications in desalination, ...water treatment, and energy conversion. Two-dimensional nanofluidics provide platforms to utilize this phenomenon for capturing osmotic energy. However, it is challenging to further improve the power output with inadequate charge density. Here we demonstrate a feasible strategy by employing Kevlar nanofiber as space charge donor and cross-linker to fabricate graphene oxide composite membranes. The coupling of space charge and surface charge, enabled by the stabilization of interlayer spacing, plays a key role in realizing high ion selectivity and the derived high-performance osmotic power conversion up to 5.06 W/m2. Furthermore, the output voltage of an ensemble of the membranes in series could reach 1.61 V, which can power electronic devices. The system contributes a further step toward the application of energy conversion.
Biological ion channels, as fundamental units participating in various daily behaviors with incredible mass transportation and signal transmission, triggered booming researches on manufacturing their ...artificial prototypes. Biomimetic ion channel with the nanometer scale for smart responding functions has been successfully realized in sorts of materials by employing state-of-art nanotechnology. Ion track-etching technology, as crucial branches of fabricating solid-state nanochannels, exhibits outstanding advantages, such as easy fabrication, low cost, and high customization. To endow the nanochannel with smart responsibility, various modification methods are developed, including chemical grafting, non-covalent adsorption, and electrochemical deposition, enriching the reservoir of accessible stimuli-responses combinations, whereas were limited by their relatively lengthy and complex procedure. Here, based on the electric field induced self-assembly of polyelectrolytes, a universal customizable modifying strategy has been proposed, which exhibits superiorities in their functionalization with convenience and compatibility. By using this protocol, the channels’ ionic transport behaviors could be easily tuned, and even the specific ionic or molecular responding could be realized with superior performance. This strategy surely accelerates the nanochannels functionalization into fast preparing, high efficiency, and large-scale application scenarios.
Nanofluidic membranes offer exceptional promise for osmotic energy conversion, but the challenge of balancing ionic selectivity and permeability persists. Here, we present a bionic nanofluidic system ...based on two-dimensional (2D) copper tetra-(4-carboxyphenyl) porphyrin framework (Cu-TCPP). The inherent nanoporous structure and horizontal interlayer channels endow the Cu-TCPP membrane with ultrahigh ion permeability and allow for a power density of 16.64 W m
, surpassing state of-the-art nanochannel membranes. Moreover, leveraging the photo-thermal property of Cu-TCPP, light-controlled ion active transport is realized even under natural sunlight. By combining solar energy with salinity gradient, the driving force for ion transport is reinforced, leading to further improvements in energy conversion performance. Notably, light could even eliminate the need for salinity gradient, achieving a power density of 0.82 W m
in a symmetric solution system. Our work introduces a new perspective on developing advanced membranes for solar/ionic energy conversion and extends the concept of salinity energy to a notion of ionic energy.
In nature, ultrafast signal transfer based on ion transport, which is the foundation of biological processes, commonly works in a hydrogel–water mixed mechanism. Inspired by organisms’ hydrogel-based ...system, we introduce hydrogel into nanofluidics to prepare a hydrogel hybrid membrane. The introduction of a space charged hydrogel improves the ion selectivity evidently. Also, a power generator based on the hydrogel hybrid membrane shows an excellent energy conversion property; a maximum power density up to 11.72 W/m2 is achieved at a 500-fold salinity gradient. Furthermore, the membrane shows excellent mechanical properties. These values are achievable, which indicates our membrane’s huge potential applications in osmotic energy conversion.
Osmotic energy between river water and seawater has attracted interest as a new source of sustainable energy. Nanofluidic membranes in a reverse electrodialysis configuration can capture energy from ...salinity gradients. However, current membrane materials suffer from high resistances, low stabilities, and low charge densities, which limit their further application. Here, we designed a high-performance nanofluidic membrane using carboxylic cellulose nanofibers functionalized with graphene oxide nanolamellas with cement-and-pebble microstructures and stable skeletons for enhanced ion transmembrane transport. By mixing artificial river water and seawater, the composite membrane achieved a high output power density up to 5.26 W m
−2
. Additionally, the membrane had an excellent acid resistance, which enabled long-term use with over 67 W m
−2
of power density. The performance of this composite membrane benefited from the mechanically strong cellulose fibers and the bonding between nanofibers and nanolamellas. In this work, we highlight promising directions in industrial waste treatment using energy extracted from chemical potential gradients.
Highlights
The first construct of a multi-field-coupled synergistic ion transport system (MSITS) in Li
+
extraction is proposed.
Effectively suppress the ion concentration polarization effect of the ...ion-enrichment zone at the membrane interface.
The MSITS equipped with heterogeneous membrane exhibited outstanding separation performance with Li
+
flux of 367.4 mmol m
−2
h
−1
and Li
+
/Co
2+
selectivity of 216,412, outperforming previous reports.
The global carbon neutrality strategy brings a wave of rechargeable lithium‐ion batteries technique development and induces an ever-growing consumption and demand for lithium (Li). Among all the Li exploitation, extracting Li from spent LIBs would be a strategic and perspective approach, especially with the low energy consumption and eco-friendly membrane separation method. However, current membrane separation systems mainly focus on monotonous membrane design and structure optimization, and rarely further consider the coordination of inherent structure and applied external field, resulting in limited ion transport. Here, we propose a heterogeneous nanofluidic membrane as a platform for coupling multi-external fields (i.e., light-induced heat, electrical, and concentration gradient fields) to construct the multi-field-coupled synergistic ion transport system (MSITS) for Li-ion extraction from spent LIBs. The Li flux of the MSITS reaches 367.4 mmol m
−2
h
−1
, even higher than the sum flux of those applied individual fields, reflecting synergistic enhancement for ion transport of the multi-field-coupled effect. Benefiting from the adaptation of membrane structure and multi-external fields, the proposed system exhibits ultrahigh selectivity with a Li
+
/Co
2+
factor of 216,412, outperforming previous reports. MSITS based on nanofluidic membrane proves to be a promising ion transport strategy, as it could accelerate ion transmembrane transport and alleviate the ion concentration polarization effect. This work demonstrated a collaborative system equipped with an optimized membrane for high-efficient Li extraction, providing an expanded strategy to investigate the other membrane-based applications of their common similarities in core concepts.
The infections and diseases caused by harmful bacteria are regarded as the worldwide health-threatening issue. The most antibiotics-based delivery systems restricted the controlled drug release at ...specific infection sites due to the stable chemical conjugation, thus largely compromising the treatment effectiveness. Herein, we report the construction of light controlled drug-based supramolecular polymer (LDSP), which is endowed the “switch on” function for realizing the controllable antibiotics released in specific sites. LDSP was first formed based on the host-guest interaction between β-cyclodextrin units grafted hyaluronic acid chain (HA-CD) and azobenzene moiety linked by two enoxacin units (Azo-(Eno)2), and could further self-assemble into light controlled drug-based supramolecular polymer self-assemblies (LDSPSAs). Under the UV light irradiation, the “switch on” function of LDSPSAs could be effectively turned on at the specific infected tissues due to the smartly dissociated host-guest interaction, facilitating the controlled release of the hydrophobic Azo-(Eno)2 to interact with bacteria for efficient antibacterial effect. The biological evaluation demonstrated that LDSPSAs achieved good antibacterial efficiency and well biosafety.
With the rapid development of the lithium ion battery industry, emerging lithium (Li) enrichment in nature has attracted ever-growing attention due to the biotoxicity of high Li levels. To date, fast ...lithium ion (Li+) detection remains urgent but is limited by the selectivity, sensitivity, and stability of conventional technologies based on passive response processes. In nature, archaeal plasma membrane ion exchangers (NCLX_Mj) exhibit Li+-gated multi/monovalent ion transport behavior, activated by different stimuli. Inspired by NCLX_Mj, we design a pH-controlled biomimetic Li+-responsive solid-state nanochannel system for on-demand Li+ detection using 2-(2-hydroxyphenyl)benzoxazole (HPBO) units as Li+ recognition groups. Pristine HPBO is not reactive to Li+, whereas negatively charged HPBO enables specific Li+ coordination under alkaline conditions to decrease the ion exchange capacity of nanochannels. On-demand Li+ detection is achieved by monitoring the decline in currents, thereby ensuring precise and stable Li+ recognition (>0.1 mM) in the toxic range of Li+ concentration (>1.5 mM) for human beings. This work provides a new approach to constructing Li+ detection nanodevices and has potential for applications of Li-related industries and medical services.
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