Key Takeaways & Executive Findings
- •• • The ADM achieves a water permeability of 288 L/(m2 h bar), significantly higher than commercial NF membranes, enabling low-pressure operation and reduced energy costs. • • The dual-affinity design (electrostatic Cl− and hydrophobic AOT) lowers the free energy barrier for PFAS adsorption, enhancing binding strength and range, as confirmed by molecular dynamics simulations. • • Electrochemical regeneration by reversing the applied potential allows long-term operation without secondary waste, addressing a key limitation of conventional adsorption methods. • • Scalability is demonstrated with large-area membranes (625 cm2) assembled into modules capable of treating liters of contaminated water per hour, maintaining consistent PFAS removal, indicating industrial feasibility.
Abstract
Per- and polyfluoroalkyl substances (PFAS), known as 'forever chemicals,' pose significant environmental and health risks due to their extreme persistence. Chronic exposure, even at low levels, is linked to cancers, thyroid disruption, immune suppression, and developmental issues. In 2024, the US EPA set maximum contaminant levels of 4 ng/L for PFOA and PFOS in drinking water, necessitating advanced treatment technologies. Existing methods include non-destructive adsorption and ion-exchange, which require high adsorbent doses and generate secondary waste, and destructive methods like chemical oxidation and photocatalysis, which are energy-intensive and slow. Membrane processes such as nanofiltration (NF) and reverse osmosis (RO) are effective but demand high operating pressures and frequent maintenance. Liu et al. recently reported in Nature Water an electro-activated dual-affinity membrane (ADM) integrating hydrophobic and electrostatic binding sites on a polypyrrole (PPy) functional layer. By applying a short positive potential, chloride ions (Cl−) and dioctyl sulfosuccinate (AOT) are oriented to create complementary adsorption domains: Cl− provides electrostatic sites for sulfonic/carboxyl groups, while AOT introduces hydrophobic domains for fluorinated carbon chains. The ADM achieves high removal rates for PFOA, PFOS, and PFNA under low operating pressures, with a water permeability of 288 L/(m2 h bar), outperforming commercial NF membranes. Electrochemical regeneration by potential reversal enables long-term operation. Molecular dynamics simulations and energy decomposition analyses reveal synergy between electrostatic and hydrophobic interactions, lowering free energy for adsorption. Scalability was demonstrated with large-area membranes (625 cm2) assembled into modules treating liters per hour, maintaining consistent PFAS removal.
1. Introduction
PFAS contamination of drinking water sources is a critical global issue, with regulatory limits now set at 4 ng/L for PFOA and PFOS by the US EPA. Conventional treatment technologies face significant bottlenecks: adsorption and ion-exchange require high doses and produce secondary waste; destructive methods are energy-intensive and slow; and membrane processes like NF and RO demand high operating pressures and frequent maintenance, increasing costs and reducing productivity.
The electro-activated dual-affinity membrane (ADM) developed by Liu et al. directly addresses these limitations by integrating hydrophobic and electrostatic binding sites on a polypyrrole layer. This design enables efficient PFAS capture under low pressures, with high water permeability and electrochemical regeneration, offering a scalable, cost-effective solution for PFAS-free drinking water.
Loading authentic research manuscript (Pages 1–5)...
Sharafat Ali, Xianshe Feng (2026). Electro-activated Dual-Affinity Membranes for PFAS-Free Drinking Water: A Paradigm Shift in Separation Technology. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-025-3758-y
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the maximum operating pressure required for the ADM to achieve high PFAS removal rates, and how does this compare to conventional NF/RO systems?
The ADM operates under low operating pressures, though exact pressure values are not specified in the abstract. However, its high water permeability of 288 L/(m2 h bar) indicates that it can achieve high flux at lower pressures compared to commercial NF membranes, which typically require pressures of 5-20 bar. This reduces energy consumption and operational costs.
How does the electrochemical regeneration process affect the long-term stability and performance of the ADM?
The ADM can be regenerated electrochemically by reversing the applied potential, which releases captured PFAS and restores binding sites. This enables long-term operation without significant performance decline, as demonstrated in the study. The regeneration process avoids the need for chemical cleaning or replacement, reducing downtime and secondary waste.
What is the selectivity of the ADM for different PFAS compounds, and does it effectively remove short-chain PFAS that are often more challenging?
The study reports high removal rates for PFOA, PFOS, and PFNA, which are long-chain PFAS. The dual-affinity mechanism, combining electrostatic and hydrophobic interactions, is designed to attract fluorinated carbon chains, suggesting potential effectiveness for a range of PFAS. However, specific data on short-chain PFAS (e.g., PFBA, PFBS) are not provided in the abstract, and further studies may be needed to confirm broad-spectrum removal.
What is the energy consumption per cubic meter of water treated by the ADM module, and how does it compare to existing NF/RO systems?
The abstract does not provide explicit energy consumption figures. However, the low operating pressure and high permeability imply lower energy requirements compared to NF/RO, which typically consume 0.5-2 kWh/m3. The electrochemical activation and regeneration steps may add some energy demand, but the overall process is expected to be more energy-efficient due to reduced pressure needs.
What is the fabrication cost of the ADM on a large scale, and is it economically competitive with current adsorbent-based or membrane technologies?
The abstract does not provide cost data. However, the use of polypyrrole, a conductive polymer, and the simple electrochemical activation process suggest potential for cost-effective manufacturing. The scalability demonstrated (625 cm2 membranes) indicates feasibility for industrial production. A detailed techno-economic analysis is necessary to compare with existing technologies, but the reduced energy and maintenance costs may offset initial material costs.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.