Janus Nanofiber Membranes Purify Air, Block Water, and Kill Bacteria

admin — Mon, 01 Sep 2025 08:31:46 +0000

*New publication from EMSR* Airborne pathogens and pollution control typically necessitate multiple membranes, each specializing in efficient aerosol filtration, moisture regulation, or antimicrobial protection. Integrating all these functions into a single membrane is highly advantageous but remains inherently challenging due to material incompatibility and inevitable performance trade-offs. Here, we present a photoactive Janus nanofibrous membrane for highly efficient air purification, engineered via sequential electrospinning. This asymmetric membrane features a biomimetic cactus spine and pollen structures formed within a hydrophilic biopolymer matrix with the embedding of nitrogen-doped carbon quantum dots (N-CQDs) on one side and hydrophobic microchannels on the other, together creating interfacial chemical gradients that drive unidirectional water transport. The nanofibrous membranes exhibit simultaneous size-exclusion sieving and electrostatic capture through quantum-confined charge polarization, achieving over 99.59% retention of PM_0.3 aerosols. Under UV activation, the N-CQDs generate tunable reactive oxygen species, enabling contact-free pathogen inactivation, which is further enhanced by water-mediated destabilization of microbial cell membranes, resulting in a 6-log (99.9999%) reduction of both Gram-positive and Gram-negative bacteria within 30 min. The membranes demonstrate exceptional operational durability, retaining 98.5% filtration efficiency after 10 working cycles, outperforming conventional membranes susceptible to water moisture-induced degradation. This work presents a versatile platform for advanced multifunctional air purification membranes, enabling a wide range of applications spanning biomedical isolation gowns, smart ventilation systems, and reusable respiratory devices.

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Multifunctional Photoactive Janus Nanofibrous Membranes for Unidirectional Water Transport and Remediation of Airborne Pathogens and Pollutants

Y. Rao, J. Chen, G. Li, J. Liu, X. Deng, S. Feng, C. Lu, Z. Low, Z. Zhong, W. Xing

ACS Nano, 2025, in press

From Batteries to Brines: Inorganic Solid‑State Electrolytes as Lithium‑Selective Membranes

admin — Tue, 26 Aug 2025 02:23:31 +0000

*New publication from EMSR* In this work, we highlight inorganic solid-state electrolytes (ISSEs), originally engineered for all-solid-state batteries, as highly selective, energy-efficient membranes for extracting lithium from seawater and brines, addressing rising demand and the vast but dilute oceanic resource. Surveying oxide, sulfide, and emerging halide (and related) chemistries, the review identifies oxide-based NASICON-like materials such as LAGP, LATP, and LLTO as current leaders due to their aqueous stability, while also noting the promise of halides for fast 3D Li⁺ transport and the conductivity advantages of sulfides despite their moisture sensitivity. Lithium selectivity stems from an anhydrous vacancy-hopping mechanism that enables near-exclusive Li⁺ transport relative to competing cations, and recent device advances, including dual-channel architectures, pulsed-voltage operation, mixed-matrix membranes, and scalable flexible formats, underscore rapid progress toward practical deployment. The article outlines key challenges and opportunities, including deeper mechanistic insight under operando aqueous conditions, improved durability via doping and coatings, and scalable, uniform fabrication to translate ISSE membranes into industrial lithium recovery.

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Inorganic Solid-State Electrolyte Membranes for Lithium Extraction

Z. Low, Q. Zhang, Q. Wang, Z. Wang, Z. Zhong, W. Xing, H. Wang

Nature Reviews Materials, 2025, 10, 397

Space-Confined Synthesis of Organic Framework Membranes for Blue Energy Harvesting

admin — Sat, 26 Jul 2025 04:21:45 +0000

*New publication from EMSR* Osmotic energy, an infinite, clean energy source, can be efficiently harnessed through reverse electrodialysis using ion-selective membranes. While polymeric membranes are excellent candidates due to their solution-processability and scalability, their non-uniform pore architecture and high resistance limit their power density output. Here, an in situ space-confined synthesis strategy is proposed to fabricate sulfonated covalent organic frameworks within a sulfonated polymeric network, resulting in interconnected, well-defined ion channels. This allows a maximum power density reaching up to 40.33 W m⁻² under a 500-fold salinity gradient and a real-world power density of 14.84 W m⁻² when extracting osmotic energy from natural seawater and river water. This study underscores the potential of space-confined synthesis strategies in creating flexible and scalable ion-selective membranes for efficient salinity gradient energy harvesting, marking a significant step toward their practical applications.

Space-Confined Synthesis of Sulfonated Covalent Organic Framework‒Polymer Membranes for Enhanced Osmotic Energy Conversion

Y. Guo, X. Sun, Q. Zhang, Z. Low, H. Wang, Y. Zhu, L. Jiang

Small, 2025, e08217

Featured article – EMSR

Janus Nanofiber Membranes Purify Air, Block Water, and Kill Bacteria

From Batteries to Brines: Inorganic Solid‑State Electrolytes as Lithium‑Selective Membranes

Space-Confined Synthesis of Organic Framework Membranes for Blue Energy Harvesting