Search Results (505)

Aqueous zinc-ion batteries are promising candidates for large-scale energy storage as high-safety, low-cost, and abundant zinc resources. Compared with conventional zinc foil, zinc powder (Zn-P) anodes display controllable capacity by regulating zinc powder loading, electrode thickness and pore structure, providing opportunities to improve zinc utilization, reduce costs and enhance manufacturing compatibility. However, Zn-P anodes are dynamic particle-composite electrodes in which reaction interfaces, pore channels, particle contacts, and electronic networks continuously evolve during cycling and storage. Their electrochemical behavior therefore reflects coupled effects of Zn²⁺ plating/stripping, hydrogen evolution, corrosion, by-product-induced pore blockage, stress evolution, contact loss, and calendar aging. This review focuses on the structural characteristics, failure mechanisms, interfacial reaction regulation, electrode engineering, and practical evaluation of zinc powder anodes. It subsequently analyzes the application boundaries of zincophilic metals, carbon materials, MXene, Meta–Organic Frameworks/Covalent Organic Frameworks (MOFs/COFs), artificial interphases, electrolyte additives, slurry engineering, current collectors, and manufacturing strategies. Then, it points out their mechanisms for regulating reaction selectivity, ion/electron transport, and structural stability. Further, the practical evaluation criteria are given, including Zn loading, the negative/positive capacity ratio (N/P ratio), Zn utilization, electrolyte dosage, calendar life and pouches/large-scale cells under limited zinc conditions. Overall, Zn-P anode development should focus on interfacial reaction selectivity, powder structure, electrode manufacturing and limited-zinc evaluation. Full article

Water retention on the lunar surface is governed by water–mineral interactions, yet the atomic-scale transition from isolated adsorption to high-coverage water accumulation remains insufficiently understood. We perform spin-polarized first-principles calculations to investigate single- and multi-water adsorption on representative surfaces of four major lunar regolith minerals: CaAl₂Si₂O₈, MgFeSi₂O₆, FeTiO₃, and Mg₃FeSi₂O₈. Single-water adsorption reveals that H₂O preferentially anchors at exposed metal sites via O-M coordination, with Ti and Fe sites exhibiting stronger initial binding than Mg, Ca, or Al sites. The Hard–Soft Acid–Base (HSAB) principle provides a qualitative framework for this low-coverage site preference based on Lewis acidity. Specifically, the accessible d-orbitals and localized states of Ti/Fe centers introduce substantial covalent orbital coupling and interfacial polarization, which effectively reinforce the binding with the hard O-donor of water. However, as water coverage increases, the stabilization mechanism undergoes a fundamental transition. At low coverage, adsorption is localized and site-specific, governed by cation acidity. At high coverage, the formation of laterally connected hydrogen-bonded networks becomes the dominant stabilizing factor, and the overall adsorption behavior is increasingly dictated by surface topology and geometric compatibility for hydrogen-bond connectivity rather than by isolated cation acidity. This coverage-dependent evolution from electronic-driven anchoring to topology-driven network formation establishes a dual-stage cooperative mechanism for water accumulation on lunar mineral surfaces. Our findings suggest that models for volatile retention on airless bodies must account for both the electronic activity of surface cations and the structural topology of mineral surfaces. Full article

Distal-less homeobox 1 (DLX1) has emerged as a promising urinary biomarker for prostate cancer. This study developed a label-free piezoelectric acoustic biosensor for selective DLX1 detection using a quartz crystal microbalance (QCM). The QCM gold electrode was sequentially functionalized with L-cysteine, graphene oxide (GO), and an amine-terminated DLX1 capture probe covalently immobilized through EDC–NHS-mediated amide bond formation. Stepwise surface functionalization was characterized by X-ray photoelectron spectroscopy (XPS), supported by contact angle measurements, X-ray diffraction, and field-emission scanning electron microscopy. XPS provided multi-element evidence for Au–S thiolate formation, GO deposition, amide coupling, probe immobilization, and Watson–Crick hybridization with the synthetic DLX1 target. Under optimized conditions, the biosensor exhibited a linear response to DLX1 concentrations and achieved a limit of detection of 81.19 nM. Non-complementary sequences, including PCA3 and SARS-CoV-2, produced frequency shifts below 9 Hz, confirming high selectivity. Comparative experiments showed that GO-mediated covalent immobilization was essential for reliable detection, whereas direct DNA attachment to bare Au generated anomalous positive frequency shifts, which were attributed to weak physisorption. The proposed platform offers a sensitive and selective strategy for quantitative DLX1 detection and may support future point-of-care nucleic acid diagnostics. Full article

The demand for lightweight, flexible, and lead-free radiation shielding for next-generation extravehicular activity suits and aerospace habitat liners is rapidly intensifying. This study investigates the structural organization and X-ray attenuation performance (10–60 keV) of polyethylenimine/graphene oxide (PEI/GO) composites with GO loadings up to 50 wt%. Microstructural evolution was systematically tracked via optical image quantification (dispersion, connectivity, and local mixing indices) correlated with micro-Raman spectral mapping. Raman analysis confirmed a structural transition at 40 wt% GO, driven by a dynamic competition between covalent amine–epoxide/carboxyl functionalization and localized π–π stacking of sp² domains. X-ray transmission and linear attenuation coefficients were evaluated using a dual approach, coupling experimental X-ray exposures with deterministic NIST XCOM calculations and stochastic Monte Carlo simulations. The results demonstrate that GO significantly amplifies low-energy photoelectric absorption due to its oxygen-rich functionalities. An anomalous thickness-dependent attenuation paradox, which can be explained by accounting for forward-scattered Compton buildup in thick blocks and spatial edge refraction along non-percolating cluster interfaces in thin films, was observed experimentally. These findings provide critical material design rules for advanced, flexible, and wearable photon shields operating without mass penalties. Full article

Gelatin hydrogels combine biological origin, biodegradability, abundant chemical functionality, and broad processability, but their native thermoreversible physical networks generally lack the stability required for sustained operation. Crosslinking overcomes this limitation while regulating hydration, mechanics, transport, degradation, and responsiveness. This review examines gelatin hydrogel crosslinking from a structure–property–function perspective, connecting molecular design with physicochemical characterization and functional performance. Temperature-induced gelation and ion-mediated physical interactions are compared with small-molecule- and coupling-agent-mediated, enzyme-catalyzed, and photoinduced covalent crosslinking strategies, highlighting their different balances among reversibility, stability, processability, and biocompatibility. Particular attention is given to the characterization methods required to relate junction chemistry and network organization to swelling, thermal behavior, mechanical response, degradation, and molecular or ionic transport. These relationships are evaluated across drug delivery and controlled release, tissue engineering and wound healing, food packaging, preservation and delivery, water remediation and environmental management, wearable sensing and bioelectronics, and energy storage. Across these fields, the central challenge is not to maximize crosslinking, but to balance network stability with the molecular mobility required for function. By integrating complementary crosslinking mechanisms with multiscale characterization, gelatin can be engineered as a programmable platform for advanced soft materials. Full article

High-precision two-dimensional intermolecular potential energy surfaces (PESs) for Rg–CuF (Rg = Ar, Kr, Xe) were constructed at the coupled-cluster singles and doubles with non-iterative triples [CCSD(T)] level by employing aug-cc-pVXZ (X = D, T, Q) basis sets, and the energies were extrapolated to the complete basis set (CBS) limit. All three complexes exhibit a consistent topological pattern: the global minimum corresponds to a collinear Rg–Cu–F configuration, and the local minimum corresponds to an anti-linear Rg–F–Cu configuration. As the atomic number of noble gas increases, the Rg–Cu equilibrium distance lengthens while the binding strength remarkably enhances. Bound state calculations were performed based on these PESs to yield rotational levels, which can be used to derive the intermolecular vibrational frequencies, molecular structures and spectroscopic parameters for all primary isotopologues. The predicted rotational constants B are in excellent agreement with the experimental observations, attaining a sub-MHz accuracy at the AVTZ level for Kr–CuF and at the CBS limit for Ar–CuF and Xe–CuF. Vibrational wavefunction analysis reveals that the intermolecular vibrational modes of Kr–CuF and Xe–CuF are highly localized, consistent with the pronounced molecular rigidity observed experimentally. Isotopic effect analysis reveals a well-defined linear relationship between the changes in the rotational constant B and the intermolecular vibrational frequency in relation to the reduced mass of the complex, which provides a reliable basis for predicting spectroscopic parameters of unobserved isotopologues. Symmetry-adapted perturbation theory (SAPT) energy decomposition further demonstrates that the Rg–Cu interaction is dominated by induction forces, with significant contributions from dispersion and electrostatics, and exhibits notable charge transfer character. This polarization and orbital overlap transcend the conventional van der Waals picture and reveal a partially covalent nature in noble gas transition metal interactions. Full article

Safe transfusion depends on rapid, accurate ABO typing, yet reference methods require centrifuges and instrumentation unavailable at the point of need. Here, a paper-based ABO-RhD typing device built on a covalent, optically silent surface chemistry is reported. Aminosilane (APTES) and epoxysilane (GPTMS) functionalisation of Whatman cellulose was compared by water contact angle, energy-dispersive X-ray spectroscopy (SEM-EDS) and infrared spectroscopy (FT-IR) across two paper grades, three silane concentrations (5, 10 and 20% v/v) and three reaction times (1–6 h). APTES produced a strongly hydrophobic layer that impeded aqueous wicking, and its glutaraldehyde activation generated a red-brick chromophore incompatible with a red-channel readout. GPTMS coupled antibodies in a single mild step, without a crosslinker or visible chromophore, while preserving wicking. GPTMS (10% v/v, 3 h, Whatman No. 4) with a six-cycle 100 µL saline wash was selected; antibodies were immobilised in a four-zone layout (anti-A, anti-B, anti-D and control) within a 3D-printed two-compartment housing that traps agglutinated cells while free cells wash through. On 80 EDTA clinical blood samples (20 each of groups A, B, AB and O) the device classified every sample correctly (accuracy 100%; 95% confidence interval 95.4–100%), with visual and instrumented reads in full agreement. All samples were RhD-positive, so the anti-D channel is validated here for the positive call. Full article

Polymeric antistatic additives offer improved resistance to migration compared with low-molecular-weight agents, but high loadings are generally required to establish effective charge-dissipation pathways in nonpolar polypropylene (PP). Herein, a series of quaternary ammonium salt-functionalized polyamide 6/polyethylene glycol elastomers (QASPA6PEG) was synthesized by melt copolymerization and used as multifunctional antistatic additives for PP. Increasing the nominal QAS content decreased the surface resistivity of the elastomers from 3.24 $\times$ 10⁹ Ω to 9.71 × 10⁸ Ω. The elastomers were subsequently melt-blended with PP at loadings of 10–20 wt% using maleic-anhydride-grafted polypropylene as a compatibilizer. The surface resistivity of the blends decreased with increasing QAS content and elastomer loading, consistent with the formation of increasingly interconnected ion-conducting domains. The blend containing 20 wt% 0.4QASPA6PEG exhibited surface resistivities of 3.64 $\times$ 10¹¹ Ω and 4.69 $\times$ 10¹⁰ Ω on days 0 and 60, respectively. Its saturated water absorption reached 4.38%, compared with 0.27% for neat PP, supporting a moisture-assisted ionic conduction mechanism. The measured bromine content remained nearly unchanged after 60 days of storage, indicating limited loss of the QAS-containing component. In addition to improving charge dissipation, QASPA6PEG enhanced the ductility and impact resistance of PP. At a loading of 20 wt%, 0.4QASPA6PEG increased the elongation at break from 358 ± 23% to 690 ± 81% and the notched impact strength from 3.16 ± 0.37 to 4.93 ± 0.45 kJm⁻². These results demonstrate that covalently introducing ionic structures into PA6/PEG elastomers is an effective strategy for coupling antistatic modification with toughening in PP. Full article

In the era of global energy transition, the development of third-generation photovoltaic technologies, such as dye-sensitized solar cells, has emerged as a paramount challenge in materials engineering. This study is dedicated to the synthesis and implementation of graphene quantum dots as eco-friendly sensitizers within DSSC architectures. The GQDs were synthesized via a microwave-assisted hydrothermal route using biodegradable organic precursors, providing a “green” alternative to conventional, toxic heavy-metal-based materials. The nanocrystalline structure and optoelectronic properties of the sensitizer were verified through UV-Vis and visual photoluminescence assessment. A focal point of this research was the optimization of the GQD concentration on the mesoporous surface of the titanium dioxide photoanode. Measurements were conducted utilizing a custom-designed experimental setup integrated with 3D-printed (FDM) components and an Arduino microcontroller, ensuring precise data acquisition under controlled illumination conditions (405–625 nm). The results indicated an optimal operational point at a fivefold dilution of the stock solution (0.4 g/dm³), which yielded the highest open-circuit voltage ($V_{\mathrm{oc}}$) of 545.4 mV under UV irradiation. The decline in photovoltaic performance observed at higher concentrations was attributed to excessive nanostructure agglomeration, which effectively blocked the mesopores of the semiconductor. Furthermore, the demonstrated high chemical capacitance of the system imparts electrochemical capacitor-like characteristics to the cell, enabling energy stabilization under fluctuating illumination. To elucidate the underlying sensitization mechanisms at the atomic level, computational simulations were conducted utilizing the MACE machine-learning potential and the GFN2-xTB semi-empirical method. The theoretical models revealed that the formation of stable covalent Ti–O–C bridges (chemisorption) is imperative for establishing strong interfacial electronic coupling. Solvation models and molecular dynamics (MD) at 300 K confirmed the thermodynamic and operational robustness of the hybrid system in an aqueous electrolyte. Ultimately, this combined experimental and theoretical work conclusively demonstrates that graphene quantum dots represent an efficient, highly stable, and non-toxic alternative to classic molecular dye sensitizers. Full article

Localized therapeutic delivery has gained increasing attention as an effective strategy in enhancing treatment efficacy while at the same time minimizing systemic side effects. However, conventional hydrogel-based therapeutic delivery systems often suffer from poor tissue retention and insufficient control over delivery. This drawback is highly pronounced in wet and dynamic biological environments. So, catechol-based adhesive hydrogels have emerged as promising biomaterials for localized therapeutic applications and are inspired by the remarkable wet-adhesion capability of marine mussels. As a highlight, catechol chemistry enables robust tissue adhesion through multiple intermolecular interactions, including hydrogen bonding, metal coordination, and covalent coupling. At the same time, it contributes to hydrogel cohesion and structural stability. Recent advances in hydrogel engineering have expanded the functionality of these systems through integration of injectable formulations, self-healing networks, nanocomposite reinforcement, and stimuli-responsive biointerfaces. These developments have transformed adhesive hydrogels from tissue sealants into multifunctional therapeutic platforms capable of enhancing tissue retention, regulating therapeutic release, and dynamically interacting with biological microenvironments. Here, we review molecular mechanisms underlying catechol-mediated adhesion and discuss recent progress in advanced adhesive hydrogel systems. We further highlight their therapeutic applications in wound healing, musculoskeletal regeneration, exosome and gene delivery, immunomodulatory therapies, and localized cancer therapy. Finally, current translational challenges and future opportunities in developing next-generation smart biointerfaces for precision regenerative medicine are discussed. Full article

This study developed surface-functionalized polylactic acid (PLA) films by depositing electrospun gelatin/chitosan (GE/CH) nanofibrous coatings formulated with and without bioactive phenolic compounds (curcumin and anthocyanin). Evaluating various polymer blending ratios and operational parameters revealed that a GE:CH ratio of 7:3 (v/v), processed at an applied voltage of 25 kV and a collector speed of 300 rpm, provided the most stable electrospinning behavior among those tested, yielding a uniform nanoscale fibrillar network. The deposition of this selected GE/CH layer onto the PLA substrate significantly improved the composite bilayer film’s tensile strength and oxygen barrier properties, although it increased macroscopic opacity. Furthermore, active coatings containing 0.25% and 0.50% (w/w) curcumin or anthocyanin were successfully processed. This 0.50% level was the maximum concentration quantitatively evaluated in the present study, as preliminary observations suggested poorer processability at higher concentrations, which induced premature gelation and needle clogging. While interactions (mostly non-covalent physical interactions) associated with the phenolic compounds synergistically reinforced the mechanical rigidity and reduced the water vapor permeability of the bilayer films, the macroscopic bioactive functionality was limited. The low loading concentrations, coupled with severe optical masking and restricted aqueous extraction, resulted in moderate antioxidant activity (10.31–30.46% DPPH radical inhibition) and no visually detectable halochromic (pH-responsive) color changes. Overall, these findings highlight a significant functional trade-off in the design of active coatings, where structural and mass transport barrier enhancements are achieved, but macroscopic bioactive functionality is constrained, underscoring the necessity for advanced encapsulation strategies in future developments. Full article

Copper and its alloys are indispensable for electronics, communications, new energy systems, and aerospace engineering due to their exceptional electrical conductivity and mechanical properties. However, the thin cuprous oxide (Cu₂O) layer that naturally forms on copper and its alloys is prone to failure under elevated temperatures and high humidity, particularly in chloride-rich environments, leading to accelerated localized corrosion. While conventional chromate-based passivation has long been the industrial standard for preventing corrosion, its use has been increasingly restricted by global regulations (such as RoHS and REACH) due to its severe toxicity and health risks. To address the conflict between environmental compliance and protective performance, this review systematically evaluates recent advances in environmentally friendly, chromium-free anti-corrosion coatings in the present review. These alternative coatings are critically analyzed and categorized into four mechanistic groups: (i) inorganic conversion coatings (including molybdate, tungstate, rare earth, and phosphate systems); (ii) organic films formed via chemical or physical adsorption (such as organic inhibitors, thiol-based monolayers, and organosilane self-assembled films); (iii) conversion coatings engineered through covalent bonding, coordination chemistry, and microstructural tailoring; and (iv) multifunctional coatings that integrate self-healing capability with high electrical conductivity. Beyond providing a technical summary, this review explored how the swift progression of electronic information technology, new energy infrastructure, and robotics has imposed more exacting, multifunctional demands on copper components. This review provides a strategic roadmap for future research and prioritizes the creation of protection strategies that operate robustly in multi-physics coupling environments—integrating high conductivity, autonomous self-healing, and long-term chemical stability to ensure the reliability of next-generation infrastructure. Full article

Polyetheretherketone (PEEK) is increasingly attractive for patient-specific maxillofacial reconstruction because its elastic modulus approximates cortical bone, it is fully radiolucent, and it is compatible with additive manufacturing; its principal limitation is bioinertness, as the hydrophobic surface does not support protein adsorption or direct bone apposition. This study aimed to functionalize the surface of fused-deposition-modeling (FDM)-printed, medical-grade PEEK to increase its potential for bioactivity while preserving these bulk advantages. To this end, 3D-printed specimens of implant-grade PEEK were activated by CO₂ plasma and coated with gelatin methacryloyl (GelMA) via EDC/NHS coupling followed by UV photocrosslinking. Surfaces were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, sessile-drop water contact angle measurement, gravimetric analysis, and scanning electron microscopy (SEM). Plasma treatment introduced oxygen-containing functional groups and reduced the water contact angle from 78.3° to 6.6°. GelMA deposition following EDC/NHS coupling, consistent with covalent immobilization, was supported by characteristic amide bands and was most pronounced for the 50 mg/mL formulation, corresponding to a deposited mass of 11.81 ± 0.47 μg/mm²; SEM revealed a relatively uniform protein film along the printed filaments. These results establish a surface-functionalization route and provide preliminary physicochemical indicators of potential bioactivity for patient-specific PEEK implants, to be confirmed through in vitro and in vivo biological validation. Full article

Sulfur(VI) fluoride exchange (SuFEx) chemistry is a powerful click reaction for modular synthesis, distinguished by high chemoselectivity, broad functional-group tolerance and the formation of robust sulfur(VI)-based linkages. These attributes are particularly valuable for polymer functionalization, as S(VI)–F handles on either the polymer or the modifier enable covalent coupling under controlled conditions. This review spans SuFEx-mediated post-polymerization modification and architectural control of synthetic polymers, surface, interfacial and porous-material functionalization, and SuFEx-based conjugation and covalent capture in natural and sequence-defined biopolymers. Across these contexts, we compare the advantages, supporting mechanistic and analytical evidence, current limitations and future opportunities of SuFEx-enabled polymer functionalization. Full article

Exploring protein–protein interaction (PPI) networks during cellular processes is critical for understanding the molecular mechanisms underlying these processes. PL (proximity labeling) is an emerging technique with the potential to be a powerful protein interactomics tool. It employs proximity-labeling enzymes, coupled with mass spectrometry, to covalently label, capture, and identify interacting and neighboring proteins of the bait protein. The development of numerous novel PL enzymes and the improvement of biotin ligase-based enzymes have enabled efficient spatiotemporal mapping of PPIs, especially after the establishment of TurboID in plants. Most PL-associated reviews in plants focus on the potential applications of different enzyme-based PL. Here, we focus on PL cases effectively applied in plants and dissect each case in detail from the perspectives of PL expression design, labeling, extraction, enrichment, and quantitative proteomic identification. Moreover, we compare cases using biotin ligase-based PL (such as BioID and TurboID) and PUP-IT, highlighting the advantages and limitations of each PL system. We delineated the pipeline and optimization strategies for PL experiment design to facilitate successful execution by plant researchers. Full article