Materials Letters最新文献

Bioactive glasses are crucial in regenerative medicine, meeting the demand for biomaterial–bone tissue integration. This study explores the effect of polymer-based films on bioactive glass, evaluating their impact on biological and physicochemical properties to potentially improve cell-material interaction. Polysaccharide-based films were used to modify a silica-based bioactive glass, analyzing surface features, composition, and bioactivity upon immersion in simulated body fluid. Surface characteristics investigation confirmed successful functionalization, but no notable differences were found in bioactivity between unmodified and polymer-coated materials. Therefore, the polymer-based coating is not detrimental for the scaffold’s apatite-forming ability, and is expected to facilitate bone cell attachment, which deserves future investigation.

To reduce the carbon dioxide emissions during cement production, this research utilized seashell powder and calcined slag to replace a portion of the cement clinker, creating a novel green, low-carbon, ternary cement—seashell powder calcined slag cement (SCSC). This study investigated the impacts of seashell powder and calcined slag on the mechanical properties, hydration process, and microstructure of SCSC. The findings revealed that the addition of seashell powder and calcined slag improved the material’s toughness and promoted the formation of cementitious products such as carboaluminate phases, C-A-S-H gel, and ettringite, with a 15% mixture of seashell powder and calcined slag increasing the compressive strength ratio of SCSC to ordinary Portland cement to 112%, and reducing the proportion of large pores by 3%.

In order to enhance mechanical and tribological properties, carbon was microalloyed in a series of TiMoNbZrC_x (x = 0, 0.03, 0.05, & 0.09 wt%) based refractory high entropy alloys (RHEAs). All the RHEAs exhibited BCC as major phase with minor cubic carbide phases in C added samples. Increase in C content tend to refine microstructure attributted to Zenner pinning effect, and further enhance its hardness (from ∼610 to 727 Hv) and yield stength (from ∼1668 MPa to 1990 MPa). The lean C (0.03 wt%) content enhanced in-vitro wear resitance by an order, while higher C addition accompanied an increase in wear rate ascribed to carbide assisted third body abrasion.

This work focuses on developing novel iron-based self-lubricating composites reinforced with Ti₂SnC MAX phase produced by powder metallurgy. Two amounts of Ti₂SnC (5 and 10 vol%) and the addition of 10 vol% graphite were evaluated. The microstructure revealed a partial reaction between the matrix and the Ti₂SnC, exhibiting a degree of dissociation in the presence of graphite, leading to the precipitation of carbides. The addition of the MAX phase significantly improved the hardness and compression strength. The dry coefficient of friction was around 0.12 for Fe + 5Ti₂SnC + 10Gr, showing a remarkable reduction in wear rate up to 85 % compared to pure iron. The results demonstrate a synergistic effect between the MAX phase and graphite, enhancing tribological performance and wear resistance.

Inorganic hollow nanoparticles have received a great deal of attention as nanocarriers for drug delivery system, but it is still challenging to control the drug release time and achieve high drug delivery efficiency. In this study, we intend to build a controllable smart drug delivery system that delivers drugs to a desired location for a desired time using a stimulus-responsive material. Polyacrylic acid (PAA), a pH-responsive material, is coated on the silica–titania hollow nanoparticles (HNPs) to acquire stimulus-responsive material for controlled drug release.

Herein, the electrochemical performance of Urchin-like W₁₈O₄₉ nanospheres and ball-like ZnS nanospheres were synthesized by the hydrothermal route and compared with the composite of W₁₈O₄₉-ZnS performance. XRD, FESEM, and EDX analysis investigated the crystal structure and morphology. The electrochemical performance of W₁₈O₄₉, ZnS and W₁₈O₄₉-ZnS composite electrodes was examined by using 3 M KOH aqueous solution. The composite provides a high specific capacitance of 517 F/g at 1 A/g. Furthermore, we constructed asymmetric supercapacitor W₁₈O₄₉-ZnS||MnO₂-KOH, which provide the good energy and power density of 32.61 Wh/kg and 9610 W/kg respectively, maintaining excellent stability around 10,000 cycles with 98.1 % capacity retention at 12 A/g with Coulombic efficiency of 81.3 %, that make W₁₈O₄₉-ZnS composite promising electrode material for supercapacitor applications.

Nanozymes based on the coordination of amino acids and metal ions exhibit pronounced peroxidase (POD)-like activity, holding promising prospects in mitigating bacterial resistance caused by antibiotic misuse and harboring tremendous potential in the treatment of bacterial infections. In this study, L-/D-aspartic acid (L-/D-Asp) were individually coordinated with copper ions using a simple self-assembly approach, culminating in the creation of L-/D-hydrogel and nanofibers (L-/D-Gel and NFs) with POD-like actiity. These materials displayed excellent inhibitory effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Particularly, compared to L-/D-Gel, L-/D-NFs demonstrated excellent catalytic activity at extremely low concentrations. Moreover, our prepared nanozymes exhibited higher catalytic activity over a broader range of temperature and pH levels compared to the natural enzyme horseradish peroxidase (HRP). In summary, the prepared L-/D-Gel and NFs, as a novel type of nanozyme, hold great promise for widespread applications in the treatment of bacterial infections in wounds.

Tb-Dy-Fe alloys with 〈1 1 1〉 preferred orientation were prepared by directional solidification under high magnetic fields. The relationship between the 〈1 1 1〉 orientation degree, magnetic domain structure, magnetostrictive properties, and magnetization behavior was investigated. In the low-field region, the domain structure played a crucial role in enhancing the magnetic properties; whereas in the high-field region, the 〈1 1 1〉 orientation degree became more substantial. If the magnetic phase can be induced to orient along the 〈1 1 1〉 direction and the magnetic domain structure can be optimized by a high magnetic field, the magnetostrictive properties of the alloys will be greatly improved.

Antibacterial dynamic therapy (ADT) has been a prominent drug-free anti-bacterial approach for treating bacterial infections. Nevertheless, hypoxia and glutathione (GSH) overexpression in the infection microenvironment (IME) limit the therapeutic effect. A Pd/Ag₂S composite with photothermal characteristics and the capacity to simulate CAT/POD/GSHOx is developed to address this limitation. The CAT/POD/GSHOx-mimetic activities of Pd/Ag₂S allow the use of H₂O₂ and the consumption of GSH to enhance photodynamic therapy. In vitro antibacterial experiments demonstrate that Pd/Ag₂S possesses excellent antimicrobial potential. We construct a new platform capable of modulating the IME to enable synergistic PTT/PDT/CDT therapy for bacterial infections.

Zinc-ion hybrid capacitors (ZIHCs) as a promising energy storage system suffer from unsatisfactory capability due to mismatched pore structure and lack of active sites in the carbon cathodes. Herein, a coupling strategy of oxidation template and in-situ doping is proposed to design a P-modified carbon nanosheet with abundant through-hole channels. Phosphorus doping not only reduces the electrode/electrolyte interface impedance, but also increases the available active sites. Through-hole channels enhance the Zn²⁺ accessibility. Therefore, the assembled ZIHCs provide an ultra-high energy density of 194.23 Wh kg⁻¹. Even at 0 °C, the ZIHCs retain a superior capacity of 166.0 mAh/g and stabilize for 10,000 cycles with capacity retention of 95.33 %. This work provides new insights into the design of carbon cathodes for boosting the Zn²⁺ storage.