Advanced Materials Interfaces最新文献

A Ti-Eu thin film combinatorial library with a composition ranging from 3 to 17 at.% Eu is fabricated by co-sputtering and followed by anodic oxidation. Systematic screening of the electrical behaviour of the resulting anodic memristors revealed forming-free, analogue switching behaviour, with higher Eu content alloys (7–17 at.% Eu) demonstrating enhanced endurance and multi-level switching. The best performing alloy composition in terms of memristive behaviour is identified as Ti-15 at.% Eu, with a high-to-low resistance ratio of 10⁵ and three levels of intermediate switching. Transmission electron microscopy analysis revealed the resistive switching as being interfacial, based on ion migration intermediated by intrinsically defined nanoscale crystallites. This is further confirmed by current conduction analysis, demonstrating that the conduction is governed by field-assisted filling and depletion of trap states. The defect engineered, volatile and self-rectifying anodic memristors show promise in neuromorphic computing for mimicking synaptic functions.

Interfacial strength at the metal-adhesive joint is a pivotal parameter to define adhesive bond reliability and its overall mechanical performance. This study systematically investigates and optimizes sulfuric acid anodizing (SAA) parameters to promote the interfacial strength between aluminum Al2024 (Al) alloy and polyurethane (PU). Response surface methodology (RSM) was employed for the design of experiments by altering acid concentration, anodizing current, and time. Surface roughness and contact angle were measured to assess the effect of these parameters, while scanning electron and atomic force microscopies were employed to elucidate structure-property relationships. SAA exceptionally enhanced the interfacial strength by increasing the contact area by creating a micro- and nano-porous oxide layer, resulting in a 920% and 15 100% improvement in the single lap shear strength (SLSS) and fracture energy, respectively, after 45 min anodizing. By maximizing SLSS and minimizing cost through time, electric current, and concentration, RSM defined the optimum SAA conditions at 0.4144 M concentration, 1.0907A current, and 5.505 min; experimental measurements validated the optimized outcomes, showing respective increases of 600% and 6700% in SLSS and fracture energy. Also, the failure mode shifted from adhesive to predominantly cohesive mode. Additionally, different machine learning (ML) algorithms were trained using various combinations of anodizing and surface topography features; the most influential parameters were identified while mitigating overfitting despite the limited dataset. Among all tested ML models, support vector regression showed the highest accuracy, achieving a remarkable mean absolute percentage error of ≈11%. The study highlights the effectiveness of SAA to enhance Al/PU interface strength.

Halide Perovskites

The illustration depicts charge carriers preserving their quantum phase coherence as they traverse grain boundaries in halide perovskite thin films, revealing a striking grain-size-independent behavior. Subsequent investigations uncover that phase coherence is not limited by microstructural features but dictated largely by crystal structure (or strain). More details can be found in the Research Article by Jose L. Mendoza-Cortes, Johannes Pollanen, Richard R. Lunt, William J. Gannon, and co-workers (DOI: 10.1002/admi.202500567).

Functionally Graded Printable Wood Biomass

Ramus cellulose-mediated blends form large-scale, ambient conditions additively manufactured, and biodegradable composites able to mediate their structural capacity from micro- to macro-scale. A stiff truss turns into a strong beam and into a flexible curtain in a functionally-graded half-a-meter construct. More details can be found in the Research Article by Laia Mogas-Soldevila and -co-workers (DOI: 10.1002/admi.202500513).

Rechargeable batteries have attracted significant attention for electric transportation and storage of intermittent renewable energy. Conventional slurry coating makes random electrode microstructure with tortuous ion diffusion pathways that restrict capacity. We present a novel directional ice templating (DIT) method of making ultra-high mass loading (70 mg cm⁻²) LiNi_0.8Mn_0.1Co_0.1O₂ cathodes containing engineered electrode/electrolyte interface and aligned, fast ion diffusion channels to break the conventional energy-power trade-off. We investigated the effects of calendering to reduce electrode porosity while maintaining the interfacial vertical microstructure. Our results show a critical threshold of 30% calendering degree that exhibits the optimal combination of gravimetric and volumetric energy density, fast (dis)charging, and long-term cycling stability. The porosity of the calendered DIT cathode is compatible with that of the conventional slurry coated cathodes, but exhibits significantly higher energy densities of 367 Wh kg⁻¹ and 779 Wh L⁻¹ when the (dis)charge current is increased to 7 mA cm⁻² vs. 102 Wh kg⁻¹ and 215 Wh L⁻¹ for the slurry coated electrodes in pouch cells. Further, we built an electrode processing instrument to demonstrate the scalability of the aqueous DIT method. The developments demonstrate the feasibility of extending the DIT approach toward industrial-scale sustainable electrode manufacturing for efficient energy storage.

Polymer-ceramic composite (PCC) coatings combine functionality with mechanical robustness and flexibility, which is attractive for barrier coatings, membranes, or flexible electronics. Their fabrication is challenging, as conventional ceramic thin film methods make use of polymer-incompatible high-temperature sintering. Powder aerosol deposition (PAD) offers a solvent- and sinter-free avenue toward PCCs. An unresolved key question is how the preparation route of the composite powders dictates the PAD film formation and microstructure. To address this, we investigated PAD deposition of the system polystyrene (PS)-titanium dioxide (TiO₂). PS particles synthesized via emulsion polymerization are combined with TiO₂ particles either through dry mixing, yielding inhomogeneous powders, or through ultrasound-assisted slurry-mixing to form homogeneous powders. When deposited on polycarbonate and steel, these powders produce fundamentally different microstructures, with organized, multilayer-like films emerging from the inhomogeneous powders, and isotropic films from the homogeneous ones. These structural differences correlate with variations in crystallite size revealed by X-ray diffraction, which provided new insights into the role of internal shock absorption of the polymeric component during PAD impact. By employing a sacrificial layer, we obtained free-standing PAD-processed PCC films, which enable accurate compositional determination by thermogravimetric analysis. The fabrication of a 100 cm² flexible coating on a PET film illustrates the scalability and potential for barrier and membrane applications. This work provides a transferable blueprint for designing hybrid thin films by PAD with tunable properties, thus bridging between polymer and ceramic processing.

This work presents a scalable, bottom-up approach for doping quantum confined, 1D lepidocrocite (1DL) titanate nanofilaments (NFs) with transition metal (TM) cations Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, and Cu²⁺ to enhance their photo- and electrocatalytic properties. Here we react titanium oxysulfate with tetramethylammonium hydroxide at 80°C for 12 h at one atmosphere. By incorporating metal salts during synthesis, uniform doping within the 1DL backbone is achieved. The resulting TM-doped 1DL NFs all exhibit lower bandgap energies, E_g, than the undoped samples (3.89 eV); some by as much as 0.8 eV for Mn²⁺ at 1 mol% doping, extending optical absorption into the visible region. X-ray diffraction, scanning electron microscopy, UV–Vis spectroscopy, inductively coupled plasma analysis, and X-ray photoelectron spectroscopy confirm the successful doping and structural integrity of our materials. The photocatalytic performance of the 1 mol% doped NFs is significantly enhanced, with a 95% degradation of rhodamine 6G dye under visible light in just 30 min, compared to only 65% degradation for the undoped 1DL NFs. In electrocatalysis, the Ni-doped 1DL NFs show superior oxygen evolution reaction (OER) activity, with an overpotential of 319 mV at 10 mA cm⁻², which is lower than the 383 mV for undoped 1DL NFs. The Ni-doped 1DL also has the lowest Tafel slope of 145 mV/dec at 1 mol% doping and 143 mV/dec at 5 mol%, compared to 204 mV/dec for the undoped 1DLs, indicating faster reaction kinetics. The Ni-doped NFs also exhibit excellent stability, maintaining a constant potential at 10 mA cm⁻² for > 50 h. Adding methanol to all colloidal suspensions results in their gelation within seconds. These findings highlight the potential of TM doping as an effective strategy to optimize 1DL's electronic and photochemical catalytic properties.

Plasmonic semiconductors have attracted extensive interest in optoelectronics and photocatalysis due to their broadened absorption spectral range, hot-electron injection, and near-field enhancement. Among various plasmonic semiconductors, WO_3-x allows high concentrations of oxygen vacancies (O_V) and pronounced localized surface plasmon resonance (LSPR) effects, enabling continuous tuning of optical and electronic properties. However, the LSPR effect in WO_3-x depends critically on O_V concentration and their stability. Herein, a surface reconstruction approach (structural rearrangement forming a dense surface layer with altered stoichiometry) was employed to synthesize WO_3-x nanosheets consisting of an inner layer with rich O_V concentration and a dense WO₃ surface passivation layer, which suppresses O_V healing and thereby allows stable O_V concentration during exposure in ambient atmosphere conditions or photocatalytic reactions. The as-synthesized plasmonic WO_3-x semiconductor exhibits enhanced LSPR effect due to the formation of a dense WO₃ passivation layer on the surface, which significantly improves the efficiency and stability of photocatalytic degradation of methyl orange under visible-near-infrared light illumination. This study provides a novel approach to improve the O_V stability in plasmonic WO_3-x semiconductors, offering important insights for stabilizing O_V concentrations in various plasmonic semiconductors. This advancement facilitates the application of plasmonic semiconductors in fields such as photocatalysis and nano-optoelectronics.

We investigate the spatiotemporal response of asymmetric polymer networks fabricated by frontal photopolymerization (FPP), a directional solidification process characterized by the emergence of conversion gradients and traveling waves, previously shown to support origami assembly. Employing a model system of UV cross-linking poly(ethylene glycol) diacrylate, we examine the frontal network conversion, the chemical exchanges during solvent development, and ensuing removal during drying. We find that the coupling of diffusion-evaporation and swelling-shrinkage processes gives rise to the formation of asymmetric ‘skin’ layers resulting in dynamic curvature fluctuations in otherwise planar beams, even in the absence of spatial patterning employed in FPP origami. Building on these findings, we demonstrate the fabrication of autonomous bistable switches and self-propulsion via a snapping instability that harness the environmental response of such ubiquitous asymmetric polymer networks.