(Press-News.org)
As the global demand for clean and renewable energy continues to rise, harvesting low-grade energy sources such as salinity gradients has attracted increasing attention. However, achieving both high ion selectivity and high ionic conductivity in ion-exchange membranes remains a major challenge, limiting practical power output. Now, researchers from Qingdao University, Beihang University, and the Chinese Academy of Sciences, led by Professor Xin Sui, Professor Lilong Gao, Professor Longcheng Gao, and Professor Kunyan Sui, report a breakthrough strategy based on high-density one-dimensional (1D) ionic wire arrays for efficient osmotic energy conversion. This work provides new insights into membrane design for next-generation blue energy technologies.
Why High-Density 1D Ionic Wire Arrays Matter
• Simultaneous High Selectivity and Conductivity: Precisely constructed 1D ionic wires enable efficient counter-ion transport while effectively excluding co-ions, overcoming the long-standing trade-off in conventional ion-exchange membranes.
• Ultrahigh Channel Density: The membrane achieves an areal ionic channel density of ~1012 cm-2, among the highest reported for upscaled polymeric membranes, ensuring large ion flux under salinity gradients.
• High Power Output: The optimized membrane delivers an ultrahigh power density of 40.5 W m-2 under a 500-fold salinity gradient, significantly advancing the performance of osmotic energy conversion systems.
Innovative Design and Features
• Self-Assembled Core–Shell Ionic Wires: Through molecular design, hydrophilic imidazole groups and hydrophobic alkyl chains are incorporated into homopolymer repeat units, forming 1D ionic cores protected by hydrophobic shells that suppress swelling.
• Anti-Swelling, High IEC Membrane: The membrane exhibits an ultrahigh ion-exchange capacity (~2.69 meq g-1) while maintaining minimal swelling (<10%), ensuring stable operation in aqueous environments.
• Advanced Structural Characterization: WAXD and AFM analyses confirm hexagonally packed, high-density ionic wire arrays, validating the controlled nanoscale organization of ion transport pathways.
Applications and Future Outlook
• Outstanding Ion Selectivity: The membrane shows near-ideal anion selectivity (Cl⁻/K⁺ selectivity ~0.99), as demonstrated by I–V measurements and fluorescence probe experiments.
• Practical Energy Harvesting: High power densities of 17.0–40.5 W m-2 are achieved across 50–500-fold concentration gradients, and a power density of 16.6 W m-2 is obtained using natural seawater and river water.
• Long-Term Stability and Recyclability: The membrane maintains stable performance over long-term operation and multiple recycling cycles, retaining over 90% of its initial power density.
• Antibacterial Functionality: Imidazolium groups impart excellent antibacterial properties, addressing biofouling concerns in real marine and riverine environments.
• Design Implications: This study highlights molecular self-assembly of 1D ionic wires as an effective route to break performance limits of conventional membranes. Future efforts will focus on further optimizing channel chemistry and extending this design concept to other membrane-based energy and separation technologies.
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Advancing Thermal-Hydraulic Analysis for High-Temperature Gas-Cooled Reactors
High temperature gas-cooled reactors (HTGRs) are regarded as a key component of next-generation nuclear energy systems due to their inherent safety characteristics and high outlet temperatures. Accurate thermal-hydraulic analysis plays a central role in both reactor design and safety assessment. However, conventional thermal-hydraulic codes for HTGR typically rely on two-dimensional models and traditional numerical algorithms, which fail to meet the requirements for detailed three-dimensional ...
At present global energy transition is characterized by the development trend of “centering on renewable energy power, emphasizing both security and resilience, and pursuing multi-pathway coordination”. In China, the energy revolution has also entered a critical stage of system reconstruction. Notably, relying solely on large-scale expansion of single type of energy is no longer feasible to address the systemic challenges posed by high proportions of renewable energy consumption, energy distribution across time and space, and diversified energy needs. Against ...
The induction of respiratory mucosal immunity, characterized by secretory IgA (sIgA) and lung-resident memory T (TRM) cells, is essential for establishing robust first-line defence against viruses. While it is regarded as a critical target for next-generation SARS-CoV-2 vaccine development, current intramuscular vaccines often fail to elicit potent mucosal responses, and subunit antigens usually exhibit poor immunogenicity and limited protection against emerging variants when administered alone.
To that, an approach based on the modular "plug-and-display" assembly ...
A decade-long study has revealed that rising atmospheric CO₂ and warming work together to reduce the availability of phosphorus in rice-upland crop rotation systems, potentially threatening future food security. The research, which was led by scientists from the Institute of Soil Science of the Chinese Academy of Sciences, shows that warming plays a dominant role in redirecting phosphorus into less accessible soil pools.
The findings were published in Nature Geoscience on February 3. The journal also invited ...
As global population growth and environmental pressures intensify, ensuring stable food supplies has become increasingly difficult and urgent. Wheat is a cornerstone of global food security, providing a major source of calories for nearly 40% of the world's population. Yield improvement, however, depends not only on agronomic inputs but also on plant architecture, which governs light interception, space competition, and performance under dense planting. Traits such as plant height, tiller number, and tiller angle collectively shape canopy structure and resource-use efficiency. ...
Known as the "Queen of Climbers," the genus Clematis boasts over 300 species widely distributed across the globe. From tropical rainforests to sub-arctic regions, these plants are celebrated by gardeners for their vibrant flowers and are valued in traditional medicine. Despite their great popularity, however, scientists have long struggled to organize Clematis’ rapid species radiation into a coherent family tree of Clematis has plagued taxonomists—a challenge that has persisted since Linnaeus first described the genus in 1753,
“Previous attempts using traditional DNA sequencing methods ...
New research led by the University of Michigan is painting a more comprehensive picture of how noise pollution is impacting birds around the world.
"The major takeaway from this study is that anthropogenic noise affects many aspects of bird behavior, with some responses more directly tied to fitness," said Natalie Madden, lead author of the new study.
The research, published in the journal Proceedings of the Royal Society B, was supported by federal funding from the NASA Biodiversity and Ecological ...
As countries search for alternatives to fossil fuels, biomass has gained attention as a renewable energy source capable of reducing greenhouse gas emissions. However, not all methods of burning biomass are equally environmentally friendly. A new study provides one of the first systematic comparisons of how different biomass combustion technologies influence environmental impact, offering practical guidance for cleaner energy production.
In a study published in Energy & Environment Nexus, researchers evaluated the environmental performance of four common biomass ...
Link to video and sound (details below): https://go.hawaii.edu/KdD
A new study led by a University of Hawaiʻi at Mānoa researcher shows that avian malaria can be transmitted by nearly all forest bird species in Hawaiʻi, helping explain why the disease is present almost everywhere mosquitoes are found across the islands.
The research, published February 10 in Nature Communications, found avian malaria at 63 of 64 sites tested statewide, including areas with very different bird communities. The disease, caused by generalist parasite Plasmodium relictum, is ...
Ammonia is one of the most abundant alkaline gases in the atmosphere. When released into the air, it reacts with acidic compounds to form fine particulate matter known as PM2.5, which contributes to air pollution, climate effects, and human health risks. Identifying where ammonia originates from is essential for designing effective emission control strategies. Researchers have long relied on nitrogen isotope signatures, commonly expressed as δ15N, to distinguish between ammonia released from sources such as fertilizers, livestock waste, and agricultural activities. ...
