Journal of Materials Science最新文献

The treatment of infected bone defects remains a major clinical challenge due to the limitations of conventional systemic antibiotic therapies and the ability of bacteria to form resilient biofilms. In this context, scaffolds capable of delivering local antibacterial activity while supporting tissue regeneration represent a promising alternative. This study reports the fabrication of 3D-printed composite scaffolds composed of alginate, poly(vinyl alcohol) (PVA), and 45S5 bioactive glass, subsequently functionalized with gelatin (GEL) coatings incorporating manuka honey (MH) or oregano essential oil (OEO). Release studies showed that approximately 90% of MH and OEO were released within the first 7 days, suggesting a burst release mechanism. This translated into strong initial antibacterial activity of GEL + MH and GEL + OEO scaffolds against Staphylococcus aureus and Escherichia coli, although the effect decreased after 24 h. Based on the MIC values, OEO showed markedly higher antibacterial potential than MH against both bacterial strains, reinforcing its suitability as a potent natural agent. Cytocompatibility assays revealed that while MH and OEO in pure form displayed some cytotoxicity, their incorporation into the gelatin coating markedly reduced adverse effects, maintaining cell viability above the ISO 10993–5 threshold. These findings indicate that phytotherapeutic-functionalized gelatin coatings can provide effective short-term antibacterial protection without compromising cytocompatibility. Strategies to further optimize release profiles and prolong antibacterial activity are discussed. Overall, the developed scaffolds show strong potential for application in tissue engineering, particularly in infection-prone environments such as bone defect repair, with potential relevance to chronic wound healing applications.

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With the proliferation of electronic devices and the escalating issue of electromagnetic pollution, the development of efficient and lightweight electromagnetic wave absorbing materials has emerged as a research forefront. In this paper, NiMnO₃/polypyrrole composite materials were prepared via a combination of hydrothermal treatment and in-situ polymerization. The high-dielectric polypyrrole encapsulated microflower-like NiMnO₃ particles, forming a core–shell structure that synergistically enhanced both dielectric and magnetic losses. By regulating the polypyrrole content, the impedance matching of composite materials has been improved through multiple attenuation mechanisms, leading to excellent electromagnetic energy conversion performance. When the filling content was 20 wt% and the thickness was 3.8 mm, the composite exhibited a minimum reflection loss of −43.20 dB. Moreover, it demonstrated the widest effective absorption bandwidth in the X band and extended to the Ku band, covering 5.04 GHz from 10.64 to 15.68 GHz. As a new lightweight and broadband electromagnetic wave absorbing material, the NiMnO₃/polypyrrole composite presents a promising candidate for the advancement of microwave absorbers.

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Palladium nanomaterials (PdNMs) have emerged as a versatile class of functional nanomaterials owing to their exceptional optical properties, catalytic activity, high surface-to-volume ratio, and tunable electronic structure. These unique characteristics have enabled their widespread applications in environmental remediation, sensing, catalysis, biomedicine, and energy conversion. This review is novel due to its unique framework, comparative perspective and focus on addressing a specific knowledge gap. It provided a comprehensive, up-to-date reported study on palladium nanocomposites: Synthesis, characterization and various applications. Various synthetic approaches, including chemical reduction and green bio-mediated methods, are discussed with emphasis on the influence of synthetic parameters on size, morphology, and surface chemistry. Moving beyond conventional descriptive summaries, we provide a critical, comparative analysis of functionalization strategies involving inorganic supports, including SiO₂, ZnO nanorods, graphene-based materials, and metal–organic frameworks (MOFs), to improve PdNMs’ stability, dispersibility, and catalytic recyclability. Furthermore, biomolecular and polymeric surface modifications, such as those involving quercetin, glutathione, chitosan oligosaccharide, and PEGylation, are explored regarding their capacity to confer biocompatibility, targeting capabilities, and therapeutic functionality, particularly in the context of Alzheimer’s disease and cancer therapy. In addition, recent advances in the catalytic applications of PdNMs, including Suzuki–Miyaura coupling, hydrogenation, electro-catalysis, and photocatalysis, as well as their biomedical applications in drug/gene delivery, antimicrobial and antitumor therapies, and biosensing. Finally, key challenges in scalable green synthesis, long-term biocompatibility, and structural stability are critically discussed, along with emerging opportunities in machine-learning-assisted design and multifunctional Pd-based nanohybrids. By explicitly addressing the missing synthesis-structure–function relationships across engineering and medical disciplines, this review provides a clear framework for the rational design of next-generation PdNMs for sustainable and biomedical applications.

Activated carbon for volatile organic compound (VOC) capture requires both high-density adsorption sites and accessible diffusion channels; therefore, its pore size distribution should balance adsorption and mass transfer rather than merely maximize surface area. However, for biomass precursors, direct activation or conventional activation methods often make precise pore-structure regulation difficult because the dense cellulose–hemicellulose–lignin network restricts pore opening and expansion. In this study, the preparation of bamboo-based activated carbon is redefined as a problem of “precursor activation regulation,” and it is demonstrated that introducing mild air oxidation prior to carbonization and steam activation is an effective strategy for developing a favorable micro–mesoporous structure. Air oxidation at 250 °C reshaped the bamboo precursor by increasing the fixed carbon content, increasing relative carbon enrichment, disrupting the cell wall and generating steam-activation-susceptible structural domains. After steam activation, BAC-A-250 exhibited a specific surface area of 1237 m² g⁻¹ and a total pore volume of 0.595 cm³ g⁻¹, with 0.6–3 nm narrow pores and mesopores extending to 5–15 nm. This pore architecture enabled a toluene adsorption capacity of 299 mg g⁻¹, with more than 90% of the initial adsorption efficiency retained after three adsorption–desorption cycles. Kinetic fitting and grand canonical Monte Carlo simulations revealed that micropores provided the primary adsorption sites, whereas mesopores reduced diffusion resistance. These results indicate that low-temperature air oxidation is a simple pore-structure engineering step with clear physical significance, which can be used to regulate the pore size distribution of bamboo-based activated carbon while avoiding additional post-modification treatments.

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Cellulose insulation paper greatly determines the operational stability of transformers. To further improve its thermomechanical performance, this study adopted aminophenyl-grafted ladder-like polysilsesquioxane (LPAPSQ) to modify cellulose paper. Molecular simulations with different LPAPSQ loadings were conducted, and 3% was identified as the optimal modification ratio. The mechanical and thermal behaviors of pristine and 3% LPAPSQ-modified cellulose paper were systematically compared within 343–543 K. The results demonstrate that the modified paper exhibits prominently improved comprehensive performance over pure cellulose. Mechanically, the bulk modulus, elastic modulus, and shear modulus are maximally enhanced by 29.3%, 27.8%, and 42.8%, respectively. Thermally, the introduction of LPAPSQ increases the glass transition temperature by 54 K, while reducing the mean square displacement growth rate by 53.43% and free volume fraction by 13%. The enhanced thermomechanical properties are mainly attributed to the synergistic contributions of hydrogen bonding, stable interfacial interactions, and phenyl conjugation effects. This work provides a feasible strategy for the high-performance modification of cellulose insulation paper.

Germanium selenide (GeSe) has attracted interest owing to its earth-abundant composition, environmental friendliness and high theoretical thermoelectric performance. Most studies have focused on doping and alloying strategies, while the growth of large-sized single crystals and their intrinsic properties are rarely investigated. In this work, large-sized GeSe single crystals with a (100) preferred orientation were successfully grown by the vertical Bridgman method. Angle-resolved polarized Raman spectroscopy with periodic intensity variations of the B_3g and A_g vibrational modes demonstrates pronounced structural anisotropy. Thermoelectric measurements also reveal strongly anisotropic transport properties. The thermal conductivity parallel to the (100) plane is 1.12 W m⁻¹ K⁻¹ at 600 K, approximately 1.4 times that of the perpendicular direction. In contrast, the power factor parallel to the (100) plane reaches 0.38 μW cm⁻¹ K⁻², 3.8 times that of the perpendicular direction. Consequently, the figure of merit (zT) parallel to the (100) plane is about 2.7 times that of the perpendicular direction at 600 K. Nanoindentation tests further show higher hardness and elastic modulus along the parallel direction. This work not only successfully prepares GeSe single crystals but also provides a comprehensive understanding of the intrinsic optical, thermoelectric and mechanical anisotropy of GeSe single crystal.

To address the poor interphase adhesion and mismatched strength-toughness properties between carbon fiber and epoxy matrices, this study employed electrostatic self-assembly to deposit a composite coating with a gradient brick-and-mortar structure onto the carbon fiber surface. This structure utilizes positively charged polyethyleneimine (PEI), polyetheramine (PEA), and gelatin as the “mortar,” with negatively charged graphene oxide (GO) acting as the “brick.” Their electrostatic interactions enable the ordered self-assembly of this coating onto the carbon fiber surface. Following the deposition of a six-layered, gradient brick-and-mortar (CF-L6) structure, the carbon fiber surface developed a dense and uniform coating, with its surface roughness increasing from 119 nm to 252 nm. The CF-L6-based composite showed interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) of 74.57 MPa, and 97.07 MPa, respectively, to increases of 54.87%, and 40.48% compared with the unmodified specimen. Furthermore, its tensile modulus and flexural modulus reached 18.83 GPa and 37.37 GPa, corresponding to improvements of 42.76% and 55.97% over the uncoated reference. After modification, the force-modulation curve of the CF-L6 composite exhibits favorable gradient modulus transition characteristics, with the interphase thickness increasing from 74 nm to 291 nm. The structure on the carbon fiber surface utilizes the charge properties between “brick-mortar” materials and the viscosity differences among various “mortar” components. Through cooperative assembly, it constructs a continuous gradient transition layer from “rigid” fibers to “flexible” resin, contributing to the interphase bonding between carbon fiber and epoxy resin. This approach demonstrates potential for improving the mechanical properties of the composite materials.

Stimuli-responsive materials can undergo reversible changes in their physical and chemical properties upon external or internal stimuli, displaying unique advantages in drug delivery, bioimaging, fluorescence regulation, and other related aspects. In this study, a fluorescent molecule, ((1E)-1-((4-(1,2,2-triphenylvinyl) benzylidene) hydrazineylide-ne) ethyl) ferrocene (FcMe-TPE) with aggregation-induced emission (AIE) characteristics, was designed and synthesized successfully. The micromorphology and fluorescence performance of the assemblies formed by FcMe-TPE in mixed solvents of water and dimethyl sulfoxide (DMSO) could be regulated through β-cyclodextrin (β-CD) inclusion and redox stimuli. It was found that β-CD simultaneously included both the ferrocene (Fc) moiety and the methyl group, exhibiting a binding energy of − 31.51 kcal/mol and an inclusion constant of 9.43 × 10² M⁻¹. Oxidation of FcMe-TPE enabled the regulation of the micromorphology and fluorescence behavior of β-CD-FcMe-TPE assemblies. Furthermore, by taking advantage of the competitive inclusion between amantadine (AMD) and Fc, the property of the assemblies could be further modulated upon the addition of AMD. With the increase in AMD concentration, the micromorphology transformed from the three-dimensional network structure to block aggregates, and the fluorescence intensity gradually increased. In contrast with conventional fluorescent materials, the assembly, as an organic functional optoelectronic material, exhibited significant advantages in the facile regulation of its microstructure and fluorescence performance, which provides important support for the design and preparation of new intelligent optoelectronic devices.

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The amphiphobic fluorescent molecule ((1E)-1-((4-(1,2,2-triphenylvinyl)benzylidene)hydrazinylidene)ethyl)ferrocene (FcMe-TPE) was successfully synthesized. And the tunable morphology and fluorescence behaviors of FcMe-TPE assemblies were achieved via β-CD inclusion, redox stimuli and amantadine competitive complexation.

The high-turbidity wastewater containing colloidal particles generated by industrialization and urbanization poses an urgent demand for solid-liquid separation. However, existing flocculants generally suffer from narrow operational pH windows, high dosage requirements, unstable performance in real water matrices, and risks of secondary pollution. Polyethyleneimine (PEI) alone is highly dependent on acidic conditions and only performs effectively at high concentrations. To address these limitations, this study employed a one-step graft modification strategy to functionalize PEI with a cationic polymer, poly dimethyl diallyl ammonium chloride (PDDA), and chitosan (CTS), which is rich in active sites. The two composite systems maintained over 93% removing efficiency (RE) in both simulated high-turbidity water and real water samples at ultra-low dosages, while extending the applicable pH range from acidic to near-neutral conditions. The quaternary ammonium groups of PDDA provide a sustained positive charge, enabling rapid flocculation primarily through electrostatic neutralization. In contrast, CTS introduces hydroxyl and amino groups, which facilitate hydrogen-bonding bridging and three-dimensional network entrapment, thereby sustaining stable flocculation over a broader pH range. Kinetic and isotherm fitting analyses confirm that the flocculation behaviors of both systems are dominated by chemical interactions, with differences in surface energy distribution governing their respective pH adaptability and initial response rates. Economic analysis demonstrates the feasibility of both composite materials for practical application. By comparing the structure-activity relationships of the two modification approaches, this study provides a basis for the targeted selection of flocculants under different water quality conditions.

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