Materials Letters最新文献

The Growth of discontinuous precipitates (DPs) is crucial in alloys that are strengthened by the DPs. Our research has demonstrated that DPs nucleate at grain boundaries and grow along twins and stacking faults in the (1 1 1) direction as a result of the twinning effect. Moreover, the growth rate is influenced by the wetting of grain boundaries. It restates how DPs evolute and provides a strategy by manipulating twins and stacking faults.

Core-shell electrospinning is a versatile technique for tissue engineering applications due to the possibility of uploading drugs in the core layer. The drug is protected by the shell layer that also allows its release by diffusion. The aim of the present work is the development of a drug release system for the release of doxorubicin, a chemotherapeutic agent commonly used for osteosarcoma treatment. In core–shell fibres, polycaprolactone (PCL) is often proposed for the shell layer as it is bioresorbable and biocompatible, but it is hydrophobic and lacks adhesive sites for cellular attachment. In this work, a PCL-chitosan blend was used for the shell layer to increase PCL hydrophilicity and to provide cell-recognition sites to support cell adhesion. Polyvinyl alcohol (PVA) has been used for the core layer and doxorubicin was introduced with a concentration of 100 µg/mL. Core-shell fibres of dimension of 300–500 nm were successfully obtained and doxorubicin was released in a sustained way up to 28 days.

A facile method has been developed to enhance the electrochemical characteristics of graphene by synthesizing fluorine-doped graphene (FG) slice via a hydrothermal reaction involving graphene oxide and hydrofluoric acid. The resultant FG slice demonstrates enhanced volumetric capacitance and robust cycling durability. The advancements in electrochemical behavior are owing to the integration of covalent C-F and semi-ionic C-F bonds aligned perpendicularly to the graphene planes. This FG slice is suitable for a range of practical applications, including use in sensors, as catalysts, and within the realm of nanomaterial-based electronics.

Polyimide (PI) aerogel composites were synthesized using 4,4′-diaminodiphenyl ether (ODA) and 1,3-bis(4-aminophenoxy)neopentane (BAPN) as diamine monomers, and biphenyl-3,3′,4,4′-tetracarboxylic dianhydride (BPDA) as dianhydride monomers. This study examined the impact of varying proportions of SiO₂ micron aerogel powder and the addition of BTC on the properties of the composites. The prepared composites showed ultra-high flexibility (180° folded) with the thickness of 3–4 mm, high thermal stability (95 % weight retention at 501 °C) and thermal insulation performance with ultralow thermal conductivity of 0.033 W/(K·m).

Herein, we reported a new photocatalyst InGaZn_0.3Cu_0.7O₄ with co-catalyst CuO for the photo-oxidation of tetracycline. Copper doping in InGaZnO₄ significantly reduced the bandgap and enhances the absorption of visible light. The photocatalytic performance was further enhanced by making a composite with CuO. In the photo-oxidation reaction of tetracycline, the kinetic constant of the optimal composite is 0.0111 min⁻¹, which is 3.0 and 10.1 times higher than those of InGaZnO₄ and InGaCuO₄, respectively. The photocatalytic mechanism suggested that photogenerated holes play the most important role in the oxidation of tetracycline.

Electrodeposited nickel-based coatings microalloyed with lanthanum (up to approximately 1.75 wt%) were investigated. Electrodeposition was carried out using a deep eutectic solvent containing dissolved anhydrous salts of Ni(II) and Ce(III) as precursors. Electrochemical impedance spectroscopy results revealed that microalloying the chemical composition of coatings with lanthanum leads to a significant enhancement in electrocatalytic activity towards the hydrogen evolution reaction in an alkaline medium, as well as an improvement in corrosion resistance, compared to coatings not doped with lanthanum. These findings may be used in the development of high-performance electrocatalysts for hydrogen energy.

As typical impurities in diamonds, the incorporated nitrogen (N) atoms could alleviate the wetting issues of GaN deposition on diamonds. Therefore, GaN was deposited on the N-incorporated diamond substrate. Through X-ray diffraction (XRD) characterization, the enhanced AlN was observed on the highly-N incorporated diamond substrate. Moreover, GaN morphology on N-incorporated diamond was greatly enhanced, showcasing superior film quality, which would be further confirmed by the Raman and photoluminescence spectra. Notably, high-resolution XRD characterization unveiled a much narrower rocking curve for GaN films on N-incorporated diamond substrates, with a full width at half maximum of 2714 arcsec, compared to 7560 arcsec on N-free diamond substrates. In conclusion, utilizing N-incorporated diamond substrates is a practical approach for GaN-on-diamond deposition.

The mechanical properties of 316L austenitic stainless steel (ASS) were enhanced by equal channel angular pressing (ECAP) combined with annealing treatment. High-density dislocations, twins, and slip bands are generated during 4 passes ECAP. An appropriate annealing treatment is beneficial for overcoming ductility loss and maintaining strength of ECAP samples. In this study, we found that annealing at 700 °C for 1 h and 600 °C for 12 h can achieve this goal, mainly due to the recovery of stacked dislocations at boundaries and the retention of nanoscale twins and slip bands.

Aqueous zinc-ion batteries (ZIBs) have garnered remarkable attention owing to high safety, low price, environmental friendliness, and versatile adaptability. In this paper, we present the fabrication of a fiber-based ZIB using a slurry composed of ZnVOH and carbon black as the cathode material. This battery demonstrates high capacity and a robust bonding interface. Notably, the binding strength and uniformity of the slurry on the fiber surface play a pivotal role in energy-storage capabilities. Carbon black serves the dual purpose of providing a conductive medium and a viscosity adherence to the fiber surface. ZIBs containing 15 % carbon black exhibit a high capacity of 319.8 mAh g⁻¹ at a current density of 0.5 A g⁻¹. In addition, the fully solid-state fiber battery demonstrates superior electrochemical performance under various bending deformations coupled with optimized electrical conductivity. Importantly, its seamless integration with textiles underscores its potential for large-scale industrial production of flexible fiber-shaped ZIBs, providing a compelling solution for flexible energy storage.

In this study, we report improved physical properties of selenium with multi-walled carbon nanotubes (MWCNTs) resulting from a homogeneous mixture of CNT-Se bi-layer thin film by using swift heavy ion irradiation. FESEM micrographs clearly showed the inter-diffusion of Se nanoparticles into MWCNTs following swift heavy ion (SHI) irradiation, EDX validates the elemental composition. The existence of different phonon modes (LO mode and D, G, G' bands) has been found in the Raman spectra of the investigated bi-layer thin films. UV–Visible spectroscopic analysis of pristine CNT-Se thin films show two sharp absorption edges at ∼670 nm and ∼340 nm. After swift heavy ion irradiation, the sharp absorption edge at ∼670 nm exhibits a blue shift, whereas the absorption edge at ∼340 nm exhibits a red shift, confirming the homogeneous mixing of two layers. These remarkable shifts found in the optical properties of CNT-Se bi-layer make the investigated material feasible for many optoelectronic device applications.