Materials Advances最新文献

In this work, an ion exchange-mediated sulfidation technique was adopted for the fabrication of a sulfur vacancy-assisted N-NiCo₂S₄/S-g-C₃N₄ nanocomposite (abbreviated as S′N-NCS/S-g-CN). The synergistic integration of S′N-NCS and S-g-CN, its impact on electrochemical capacitive performance and the charge storage mechanism of the nanocomposite were investigated via the power law as well as the Dunn and Trasatti methods. The S′N-NCS/S-g-CN nanocomposite offers the characteristic features of a battery-type electrode material. It delivers a specific capacity of 1034 C g⁻¹ at 1 A g⁻¹ in 2 M aqueous KOH electrolyte, and its performance significantly improved relative to pristine materials. Furthermore, it demonstrates excellent long-term cyclic stability performances and 94.1% capacitive retention after 10 000 cycles. A completely altered charge storage mechanism was observed from the diffusion-controlled (S′N-NCS) to capacitive-controlled mechanism in the S′N-NCS/S-g-CN electrode. Furthermore, the presence of sulfur vacancies and incorporated g-C₃N₄ in the S′N-NCS/S-g-CN nanocomposite induces a higher diffusion coefficient value of 2.38 × 10⁻⁷ cm² s⁻¹ relative to S′N-NCS (i.e., 2.21 × 10⁻⁷ cm² s⁻¹) and has significant impacts on the performance and efficacy of the electrode material for capacitive performances. This study reveals the energy storage performance of the compositionally engineered S′N-NCS/S-g-CN material in terms of sulfur vacancies, electrochemical kinetics, and the charge storage mechanism.

Innovative synthetic biodegradable polymers containing amino acid moieties are used as pulmonary anticancer drug delivery systems to efficiently administer drugs in a controlled manner while also altering the physical and chemical characteristics of therapeutic molecules and the way they are delivered to the lungs. In this study, the aim was to prepare a new polyamide based on L-cystine amino acid loaded with a combination of thymoquinone (TQ) and doxorubicin (DOX) nanocapsules (TQ-DOX/Cys-Py/PA NCs) to be delivered directly to the lungs. TQ-DOX/Cys-Py/PA NCs were created using a single-step interfacial polycondensation method. The aerodynamic performance assessment shows that the prepared TQ-DOX/Cys-Py/PA NCs were able to deliver 98.7% and 97.1% of the TQ and DOX nominated dose, respectively. TQ and DOX with emitted doses of 2008.2 and 110.2 μg can reach the lower parts of the respiratory system and have an aerodynamic particle size between 1 and 5 μm, which revealed that the optimum formulation would produce a small particle size (19.89 nm) with high entrapment efficiency (TQ: 85.4%, DOX: 99.49%) and loading efficiency (TQ: 52.2%, DOX: 15.03). The targeted release of TQ and DOX in 0.1 M GSH-containing buffer solution demonstrated a faster onset of action, with 50% released within the first 2 hours. In vivo studies were conducted to demonstrate the efficacy of TQ-DOX/Cys-Py/PA NCs in enabling targeted drug delivery to the lungs for the treatment of lung cancer. The results demonstrate exceptional lung targeting and sustained lung retention for at least 24 hours. Furthermore, the toxicity of the TQ-DOX/Cys-Py/PA NCs was assessed by quantifying the protein carbonyl content. The results showed that the TQ-DOX/Cys-Py/PA NCs exhibited reduced toxicity to the heart, liver, and kidney compared to free DOX and DOX/Cys-Py/PA NCs.

In this study, polycrystalline BaZr_xTi_1−xO₃ (x = 0.00, 0.05, 0.10, 0.15, and 0.20) ceramics were synthesized through a solid-state reaction technique. The effect of zirconium doping on the properties of barium titanate (BaTiO₃) was investigated by various characterization tools. The structural and morphological properties of the synthesized materials were studied by X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). The electrical properties of the Zr-doped BaTiO₃ (BZT) materials were examined by impedance spectroscopy and the optical properties were investigated using UV-Vis-NIR spectroscopy. The XRD analyses of the prepared BZT materials revealed a single-phase tetragonal structure. The inclusion of Zr⁴⁺ in the BT matrix did not significantly affect the Raman-active modes, suggesting that the tetragonal crystal structure was retained in the as-synthesized samples. FE-SEM analyses revealed that the grain size initially increased from 49.36 nm to 53.24 nm for x = 0.05 wt% and then decreased gradually for higher concentrations up to x = 0.15 wt% (26.99 nm). The dielectric constant, dielectric loss, conductivity, and quality factor determined from the impedance data demonstrated that Zr⁴⁺ addition significantly influenced the electrical properties of BT. The band gap energy, E_g, of the synthesized samples were found in the range of 3.19–3.37 eV, which was calculated from the diffuse reflection data. The experimental results suggest that the BZT ceramic materials are suitable for energy storage device applications.

We investigated the reaction mechanism of atomic layer deposition (ALD) of zirconium oxide (ZrO₂) by integrating experiments and calculations. The ALD process by alternating the supply of tris(dimethylamino)cyclopentadienyl zirconium (CpZr(NMe₂)₃) and ozone (O₃) was examined using an in situ quartz crystal microbalance (QCM) and the successive surface reaction of the Zr precursor was simulated by density functional theory (DFT) calculations. The QCM analysis suggests that two NMe₂ ligands are released during the first half-cycle of ALD. The DFT calculations indicate that the first two NMe₂ ligands are released during the chemisorption of the Zr precursor with low activation energies of 0.22 eV and 0.16 eV. Conversely, the release of the Cp ligand or the third NMe₂ ligand was unfavorable due to its endothermic nature and high activation energy. Upon completion of the chemisorption of the Zr precursor, the resulting surface species would be O₂ZrCp(NMe₂)*, which is in agreement with the QCM results. The integration of the QCM experiment and the DFT calculations is an effective approach to elucidate the ALD reaction mechanism, especially when a heteroleptic precursor is used.

Microencapsulation is an advanced technique for protecting and enhancing the processing, delivery and performance of sensitive active ingredients, such as lipid-soluble vitamins. The fabrication of microcapsules containing such materials in an efficient, cost-effective and environmentally-friendly manner remains an ongoing challenge. Multicore silica microcapsules containing α-tocopherol in their cores were fabricated through salt-induced destabilisation and subsequent agglomeration of silica nanoparticles in an oil-in-water-in-oil double emulsion template at room temperature. The primary emulsion was prepared using three different concentrations (5, 10 and 15 wt%) of the internal oil phase, i.e. a mixture of α-tocopherol and sunflower oil. The external oil phase for the secondary emulsion consisted of different concentrations of Span 80 (0, 0.5 and 1 wt%) in sunflower oil. The capsule core size does not change during storage, confirming the stability of cores within the microcapsules. Mechanical testing provides that the microcapsules containing the lowest concentration of internal oil (5 wt%) have the highest rupture force and nominal rupture stress due to the higher silica content of these microcapsules. The incorporation of Span 80 does not significantly change the adhesion of microcapsules to a Lorica Soft leather substrate, mimicking human skin. The microcapsules are designed to release their contents upon mechanical rupture induced by rubbing against skin. This work shows the potential of such microcapsules to be applied in a range of consumer products, such as cosmetics.

Suckerins, derived from the sucker ring teeth of cephalopods, have emerged as promising biomaterials for wound healing due to their unique structural properties and versatility. Suckerins exhibit a wide range of elasticity, from soft hydrogels to stiff films, controlled by β-sheet content and induced by di-tyrosine crosslinking. Compared to other natural protein-based materials, suckerins offer advantages in terms of mechanical strength, the ability to form robust supramolecular structures, biocompatibility, excellent thermoplastic property and underwater adhesion, making them suitable for wound healing and various biomedical applications. However, the full potential of suckerins in wound healing is yet to be explored. This paper aims to provide a comprehensive understanding of the structural properties, recent findings, advantages, succinylation of biomaterials and applications of natural protein-based biomaterials such as mussel adhesive protein, collagen, gelatin, silk fibroin and chitosan in wound healing, and how they stand in comparison to suckerin protein-based materials. This comprehensive review could pave the way for the development of more effective wound healing therapies. Future research directions are also discussed, emphasizing the need for a deeper understanding of the supramolecular interactions stabilizing suckerins and their potential applications in medicine, tissue engineering, nanotechnology and gaps in other protein-based materials in the context of wound healing.

The growing environmental concerns associated with traditional petroleum-based polymers have intensified the search for sustainable alternatives. This themed collection highlights innovative approaches in polymer science that prioritize sustainability without compromising performance. The featured articles encompass a spectrum of strategies, from the utilization of bio-derived monomers and biopolymers to the engineering of dynamic, self-healing materials.

Conductive hydrogels represent a promising class of novel materials to interface the human body with electronics; however, there is still a high demand for hydrogels that would truly meet the conductivity requirements for efficient signal transmission between the tissues and the device. To address this demand, herein we report the preparation of a novel pure conductive hydrogel based on PEDOT:DBSA at room temperature; thus, we offer an efficient alternative to the commonly used PEDOT:PSS, whose biocompatibility was proven to be limited. With thorough characterization, this work also contributes towards a better understanding of the relationship between the hydrogel structure and electrical properties. The mechanical strength of the novel hydrogel network is tuneable and can be easily tailored to the needs of a given application. Together with an exceptionally low value of Young's modulus, this material provides mechanical properties matching those of soft tissues. Biocompatibility tests confirmed excellent compatibility with murine endothelial cells. The total conductivity of the hydrogel is sufficient for cell-targeted bioelectronic applications, such as cell stimulation; moreover, low impedance was determined at 1 Hz, suggesting that the PEDOT:DBSA hydrogel might offer a truly functional interface between a biological tissue and an electronic device.

The double perovskite Bi_1.75La_0.25FeMnO₆ (BLFMO) ceramic was prepared by a solid-state reaction method and characterized by different techniques such as X-ray diffraction, scanning electron microscope, energy dispersive X-ray, transmission electron microscope, and optical, dielectric, and electrical property analysis. The synthesized material has a monoclinic crystal structure with an average crystallite size of 63.7 nm and lattice strain of 0.0013, as revealed by X-ray diffraction (XRD) data. The surface morphology of the prepared sample was studied by the scanning electron microscope (SEM) technique, which shows spherical-shaped well-developed grains having clear grain boundaries with an average grain size of 55.6 μm. The EDX spectrum and elemental color mapping checked the purity and homogeneity of the sample. The transmission electron microscope (TEM) technique displayed that the particles are well connected in the synthesized material, which may be a possible reason for the better physical properties. The Brunauer–Emmet–Teller (BET) surface area was 0.371 m² g⁻¹, with a pore volume of 7.202 cc g⁻¹ and an average pore diameter of 19.635 Å. The optical properties were studied from Fourier transform infrared (FTIR) and ultraviolet diffuse reflectance spectroscopy (UV-DRS). The FTIR spectrum revealed the vibrational modes of all the constituent elements in the sample. The direct bandgap energy of 2.71 eV was calculated from the UV-DRS spectrum, which is suitable for optoelectronic device applications. The sample exhibited high dielectric constant, low loss (from dielectric study), negative temperature coefficient of resistance behavior (from impedance study), non-Debye relaxation (from modulus study), and a thermally activated conduction mechanism (from ac conductivity study). The occurrence of Maxwell–Wagner dispersion was known from the dielectric study. The semi-circular arcs in the Nyquist and Cole–Cole's plots explained their semi-conducting nature. The resistance versus temperature curve indicated the semiconducting nature of the sample and its potential application as a negative temperature coefficient (NTC) thermistor. Thus, the prepared sample has unique characteristics for different applications related to optoelectronics and sensors.

NbOCl₂ exhibits exceptional nonlinear optical response, particularly for second harmonic generation (SHG). However, the environmental degradation mechanism of NbOCl₂ remains incompletely understood, posing challenges to device stability and optimization. This work demonstrates the kinetic degradation mechanism of 2D layered NbOCl₂ and proposes a strategy to improve the stability of nano-sized materials. It is primarily driven by the preferential replacement of Cl⁻ ions in NbOCl₂ with OH⁻ ions, which is regulated by storage temperature and H⁺ ions in the solution. Notably, the SHG response can be tuned effectively by altering the excitation power, degradation time, and irradiation wavelength. Additionally, the significant SHG of the NbOCl₂ nanosheets is remarkably stable when protected by poly methyl methacrylate. These findings offer novel insights into kinetic degradation mechanisms and strategies to improve the stability of NbOCl₂.