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The amount of waste electrical and electronic equipment (WEEE) is growing rapidly, yet less than a quarter of it is recycled. These "urban mines" contain valuable and critical metals that must be recovered. Therefore, developing more sustainable and energy-efficient separation techniques is essential. Membrane technology has demonstrated this capability, particularly those based on 2D materials, due to their atomic thickness and the ability to precisely tune pore size. This report introduces a novel nanofiltration membrane fabricated from charged, fully exfoliated, nanoporous 2D nanosheets. Developed for ion separation, it exhibits exceptional selectivity for silver (Ag) over other metals typically found in WEEE leachates-a feature highly relevant for solar panel recycling. Furthermore, its rare stability in acidic media makes such an approach advantageous for hydrometallurgical processes. Notably, we demonstrate that these charged 2D membranes exhibit two distinct ion transport mechanisms, intra- and inter- lamellar, to achieve remarkable and rapid separation within 2 min.

Advanced supramolecular assemblies with predefined lifetimes and rapid responses to stimuli are in high demand for applications such as biomedical delivery systems. However, such assemblies are rarely able to respond rapidly and completely to stimuli, with predictable changes in morphology. Here, we introduce monodisperse self-immolative Janus dendrimers (SIJDs) composed of hydrophilic oligo(ethylene glycol)-functionalized phenolic acid dendrons and hydrophobic monodisperse oligo(ethyl glyoxylate) chains having light-responsive end-groups. These SIJDs self-assemble into spherical nanoparticles in aqueous media. Upon ultraviolet (UV) light irradiation, the hydrophobic oligo(ethyl glyoxylate) units exhibit rapid end-to-end self-immolation within minutes. The depolymerization at the molecular level leads to a degradation pathway from spherical to crescent-shaped nanoparticles, which can be used for the rapid release of encapsulated molecules of interest.

Passive droplet control is critical for next-generation water harvesting, fluidic logic, and adaptive wetting surfaces. Here, we report a scalable, topography-free slippery liquid-infused porous surface (SLIPS) based on poly[1-phenyl-2-[p-(trimethylsilyl)phenyl]acetylene] (PTMSDPA). By selectively chemically fluorinating specific regions of the porous PTMSDPA film, followed by sequential infusion of two immiscible hydrophobic lubricants into their respective affinity-matched polymer matrices, this approach enables interfacial energy contrasts that direct droplet motion. The heterogeneous oil-infused porous surface (HOIPS) has a unique intrinsic fluorescence enabling real-time, dye-free visualization of infiltrated lubricant domains. Owing to its ultrathin (∼200 nm) and flexible polymer structure, the HOIPS enables controllable droplet motion on flat, flexible, and curved substrates without reliance on surface topography, physical confinement, or asymmetric geometries. Sub-millimeter-scale HOIPS line patterns enable controlled droplet coalescence, shedding diameter, and release timing during condensation, and optimized patterns exhibit up to 2.5× higher water-harvesting performance compared to fluorinated-oil-based SLIPS, providing a material-efficient strategy for liquid-repellent surfaces. Taken together, these results establish PTMSDPA-based HOIPS as a versatile platform for controlled droplet manipulation and condensation management.

The widespread discharge of dye-laden wastewater poses serious environmental and health threats due to its high toxicity and poor biodegradability. Conventional treatment methods are often energy-intensive and prone to secondary pollution, highlighting the need for efficient and sustainable purification materials. Herein, a green and scalable three-step strategy is developed to fabricate multifunctional ethanol-soluble polyamide/activated carbon/polydopamine/layered double hydroxide (EPA/AC/PDA/LDHs) nanofiber membranes. The process-combining blend electrospinning, biomimetic in situ polymerization, and room-temperature LDH growth-completely avoids toxic solvents and high-temperature calcination. The hierarchical porous structure, formed through the synergistic integration of AC, PDA, and LDHs, provides abundant active sites, strong interfacial adhesion, and enhanced charge transfer capability. The optimized membrane achieves removal efficiencies of 96.3% for methylene blue and 93.2% for Congo red, maintaining over 70% performance after five reuse cycles. Mechanistic studies reveal a synergistic adsorption-photocatalysis mechanism, where pollutants are captured via electrostatic attraction and π-π stacking, then degraded by reactive radicals generated under visible light through PDA-enhanced charge separation. This work offers a solvent-safe, energy-efficient, and recyclable pathway for advanced wastewater treatment and establishes a generalizable paradigm for green fabrication of environmental remediation materials.

At the operating temperature (∼750°C) of solid oxide cells (SOCs), Ni diffusion has been revealed to cause aging degradations on catalytic performance, electronic conductivity, and mechanical failures. This work discloses that Ni diffusion during the high-temperature (∼1400°C) SOC fabrication process can severely decrease the oxide ion conductivity due to Ni segregation (up to ∼7 at.%) at the YSZ (yttria-stabilized zirconia) grain boundaries (GBs). Combining electrochemical tests and advanced electron microscopy, we reveal that higher Ni enrichment leads to thicker space charge layer and higher space charge potential, which generates a significant GB blocking effect for oxide ion diffusion. We have quantitatively estimated the ionic conductivity drop induced by Ni segregation at the operation temperature range. Utilizing the ultrafast high-temperature sintering technique, we successfully mitigate Ni segregation at GBs, which can double the ionic conductivity at 700°C. This work not only clarifies that Ni segregation at YSZ GBs can significantly plague the ionic conductivity but also demonstrates that mitigating Ni segregation at YSZ GBs is a new avenue to reduce the cell's ohmic resistance and boost the SOC performance.

Despite the great self-regeneration ability of skin, severe defects require the intervention of functional dressings for effective healing. Hydrogels are ideal candidates for wound administration because of their high hydration, structural porosity, and extracellular matrix mimicking properties. Chitosan (CS) is the core matrix for building hydrogels because of its inherent biocompatibility, oxygen permeability, hemostatic, and antimicrobial activities. Through reversible cross-linking strategies with dynamic covalent bonds (e.g., Schiff base and borate-diol) and physical interactions (hydrogen bonding, electrostatic interactions, and host-guest interactions, etc.), CS-based hydrogels can dynamically adapt to the complex microenvironment of wounds. In recent years, researchers have developed smart CS hydrogel dressings with biocompatible and biodegradable, hemostatic/adhesive, antimicrobial, antioxidant, anti-inflammatory, stimulus-responsive (pH/temperature/glucose), controlled-release, and self-healing functionalities in response to diverse needs during wound healing. In acute wounds, its rapid hemostatic and infection control properties significantly accelerate healing, while for chronic wounds (e.g., drug-resistant bacteria-infected wounds, deep burns, and diabetic ulcers), it breaks down healing barriers through synergistic mechanisms including photothermal, antimicrobial, macrophage polarization modulation, reactive oxygen species scavenging, and vascular regeneration promotion. This article contains a comprehensive review of the design principles, functional optimization, and the recent progress of CS-based hydrogels for wound healing, as well as a further outlook on the future direction of hydrogel dressings in wound treatment.

Indium phosphide (InP) quantum dots (QDs) are among the most promising heavy-metal-free emitters for next-generation displays, yet achieving isotropic growth of thick ZnSe shells remains challenging because of strain accumulation and facet-dependent surface energies. Here, we report a halide-mediated, stepwise ZnSe growth strategy that produces uniform, near-spherical green-emitting InP/ZnSe/ZnS QDs with precisely tunable shell thicknesses (1.75-5.5 nm) and final sizes up to 14 nm. The resulting QDs preserve near-unity photoluminescence quantum yields (PL QYs) up to a critical ZnSe thickness of ∼3.5 nm, beyond which accumulated compressive strain at the InP/ZnSe interface generates interfacial defects and reduces PL QY. Notably, ZnSe shell contributes significantly to optical absorption, with the molar absorption coefficient at 450 nm scaling nearly with shell volume and following a clear empirical relation. A series of differently sized QDs is further assessed as blue-to-green color converters, revealing a size-dependent balance between enhanced absorption and efficient light conversion.