Journal of the Australian Ceramic Society最新文献

This research aims to develop a vinyl ester-based nanocomposite with enhanced thermal and barrier properties by integrating silicon nitride (Si₃N₄) and granite dust fillers with silane treated form. The primary objective of this research is to develop sustainable composite using waste materials. The vinyl ester resin was chosen for its favourable properties in vacuum infusion and casting processes. Moreover, Si₃N₄ particles were extracted from peanut husk through a medium temperature pyrolysis and nitration process with a size of 180 nm. Along with this the granite dust was also used as filler. Both the fillers undergo surface-modification process using 3-aminopropyltrimethoxysilane (APTMS) to enhance interfacial bonding. The composites were fabricated using solution casting method, with precise control over the mixing and curing parameters. Among various composite specimens, N4 composite contains 2 vol% of Si₃N₄, showed improved load bearing effect. Moreover, it achieved a highest mass loss stability of 99% at 415 °C due to the excellent thermal resistance of Si₃N₄. However, composite N4 also recorded the highest thermal conductivity at 0.42 W/mK, demonstrates its ability to efficiently dissipate heat. Although its water absorption was slightly higher up to 0.3%, it remains within acceptable limits for composites. In barrier property tests, composite N4 displayed a water permeability of 5.57% and an oxygen permeability of 2.63 × 10⁻² cc/m².d.atm, indicating that, despite a slight increase in water permeability, N4 effectively limits oxygen diffusion due to its ceramic-based structure. These results suggest that the composite offers a robust combination of thermal and barrier properties, making it a promising candidate for advanced coating applications where heat resistance and barrier performance are critical.

Al₂TiO₅ has received widespread attention due to its lower thermal conductivity in materials with a low coefficient of thermal expansion. Therefore, white fused corundum, tabular corundum and micro α-Al₂O₃ were selected as alumina sources to prepare Al₂TiO₅ by in-situ synthesis in this paper. The influence of alumina sources on the phase compositions, microstructure and thermal conductivity of the samples was investigated. The mechanism of the in-situ synthesis of Al₂TiO₅ was discussed in detail. The results showed that increasing the sintering temperature was beneficial for the formation of Al₂TiO₅. Besides, adding white fused corundum or tabular corundum was conducive to the preparation of Al₂TiO₅. The liquid phase formed by a small number of impurities in the raw materials at high temperatures could accelerate the diffusion velocity of Al³⁺ and Ti⁴⁺, which was beneficial to the formation of Al₂TiO₅ and the stability of its structure. The sample with tabular corundum sintered at 1600 °C had the highest content of Al₂TiO₅ about 86 wt%, and the largest average grain size of 35.3 μm. It also showed satisfactory performance, with the bulk density of 2.99 g/cm³ and the compressive strength of 98.5 MPa. Moreover, the thermal conductivity at 900 °C was reduced to 0.96 W/(m·K) compared to the sample without tabular corundum, which could be used to prepare Al₂TiO₅ ceramics with lower thermal conductivity.

Yttria stabilized zirconia (YSZ) is becoming increasingly popular in the field of dental biomaterial due to its faster production process, reduced preparation thickness, and lower cost. This study aims to compare the experimentally obtained gamma-ray absorption coefficients for YSZ dental biomaterial with theoretical data generated through GAMOS simulation and Phy-X/PSD software. The minimal µ value is determined to be 0.274 cm^–1 at an energy of 1408 keV. The µ/ρ values for the 662 keV gamma ray, derived from experimental data, GAMOS simulation, and the Phy-X/PSD algorithm, are 0.070, 0.072, and 0.074 cm²/g, respectively. As gamma energy escalates, both the half-value layer and the tenth-value layer also increase. Comparable results are obtained from both the experimental data and the datasets generated by Phy-X/PSD and GAMOS. The mean free path value is measured to be 3.645 cm using 1408 keV photons. The experimentally obtained data show good agreement with the results obtained from the GAMOS simulation and the Phy-X/PSD program.

The invention relates to the sustainable development of undoped and doped nickel oxide nanoparticles (NiO-NPs) using Zephyranthes citrina bulb extract as a bio-reductant in a solution combustion synthesis process. NiO NPs were synthesized by doping them with varying amounts of zirconium (Zr) and neodymium (Nd), enhancing their crystallinity and allowing precise control over their optical properties. Structural and morphological characteristics were confirmed using distinctive techniques. These analyses validated the NPs’ integrity, surface features, and band gap modifications. Their biological activities were assessed, including antioxidant, anti-inflammatory, antimitotic (onion root tip assay), and antidiabetic effects. Additionally, their agronomic potential was evaluated through seed germination and seedling growth studies. This environmentally friendly synthesis provides a viable path for developing NiO NPs suitable for optoelectronic and biomedical applications.

Graphical Abstract

In this study, Mn- and Ni-doped MoO₃ thin films were synthesized using a sol–gel spin coating method and evaluated as photoanodes in dye-sensitized solar cells (DSSCs). Structural, morphological, optical, and electrochemical properties of the films were systematically analyzed using XRD, SEM, UV–Vis spectroscopy, and electrochemical impedance spectroscopy (EIS). Doping with Mn and Ni resulted in a reduction in crystallite size, improved optical absorption in the UV–visible range, and enhanced electrical conductivity. The photovoltaic performance of DSSCs incorporating the doped films demonstrated a significant improvement, with power conversion efficiencies increasing from 2.4% for pristine MoO₃ to 3.375% and 5.0% for Mn- and Ni-doped films, respectively. EIS analysis revealed that Ni doping yielded the lowest charge transfer resistance (~ 15 Ω), highlighting its superior catalytic activity and electron transport capabilities. These results underscore the potential of Mn- and Ni-doped MoO₃ thin films in advancing DSSC technologies.

The primaryscope of the research is to develop and investigate the properties and performance of the composites as a uniquetactic in the material science field. This research investigates the mechanical, thermal, and machinability properties of an epoxy composite reinforced with basalt and bamboo fibers, incorporating varying concentrations of chitin. The optimized composite, EBT3 (4 vol% chitin), demonstrated superior load-bearing capacity, with fatigue life counts of 24,711, 21,711, and 18,741 cycles at 25%, 50%, and 75% UTS, respectively. Additionally, its creep behaviour exhibited minimal deformation, with values of 0.0064, 0.0069, and 0.0095 at 5,000, 10,000, and 15,000 s, indicating enhanced adhesion and interfacial bonding. In contrast, the EBT4 composite (8 vol% chitin) exhibited reduced flame propagation speed (5.31 mm/min), moderate hydrophobicity (67.52° water contact angle), and improved machinability, as evidenced by narrower kerf widths of 5.06 mm and 10.09 mm for 5 mm and 10 mm drill bits, respectively. The higher chitin content contributed to increased hydrophilicity, enhanced structural integrity, and greater thermal stability, influencing these properties. SEM analysis further provided insights into fiber-matrix bonding, filler dispersion, and agglomeration effects. Given their exceptional properties, these composites hold potential for marine, prosthetic, drone, automotive, and packaging applications.

This study investigates the enhancement of PLA-based composites through the incorporation of biosilica particles extracted from proso millet husk. The primary aim of this study is to analyse how the addition of proso millet husk derived biosilica performs in the load bearing behaviour. To evaluate this, customized filaments contains varying biosilica were produced and fabricated into composite plates via 3D printing. According to results, among the tested samples, specimen A3 (2 wt% biosilica) exhibited the best mechanical performance, attributed to uniform filler dispersion and strong matrix-filler bonding. Moreover, composite A3 showed the longest fatigue life counts of 39.9 × 10³ for 75% of ultimate tensile stress. In terms of wear performance, composite A4 (4 wt% biosilica) demonstrated the lowest specific wear rate (0.043 mm³/Nm) and coefficient of friction (0.3), although it also recorded the highest water absorption (0.27%), indicating increased hydrophilicity. SEM analysis confirmed good filler dispersion at lower biosilica content, while higher loading led to particle agglomeration. These results suggest that biosilica-reinforced PLA composites offer promising potential for eco-friendly, high-performance applications in fields such as biomedical devices, automotive components, drones, and construction materials.

This work presents an analysis of the effect of BaO incorporation on the gamma-ray attenuation properties of systematically evaluated SiO₂-B₂O₃-SrO-ZrO₂ glass matrices. Radiation shielding parameters determined using XCOM and EGS4 calculation codes were compared. There was an increase in glass density from 5.84 g/cm³ to 6.32 g/cm³ when the BaO content rose from roughly 10% to 40%. Using sophisticated WinXCom and EGS-4 calculations, the mass attenuation values (µ/ρ) of BaO doped SiO₂-B₂O₃-SrO-ZrO₂ glass systems (abbreviated BaSiBSZ) were found. This study systematically and thoroughly evaluated the effect of BaO integration on the radiation shielding capabilities of the glass system over a wide range of gamma-ray photon energies, specifically between 59.5 keV and 1332 keV. Initially, HVL (half-value layer) and MFP (mean free path) values were derived from the calculated mass attenuation coefficients. The evaluation of several crucial shielding parameters, including RPE, Z_eff, ΣR, and (k_gamma) , came next. The steady reduction of SrO oxide concentration and substitution of BaO in BaSiSBZ glass systems resulted in notable modifications in radiation protection properties. The BaSiBSZ glass systems showed a similar decrease in both HVL and MFP at a constant energy level as the BaO doping concentration was progressively raised. Concurrently, a notable enhancement was noted in RPE, Z_eff, Σ_R, and (k_gamma) coefficients. The results demonstrate that higher BaO concentrations greatly enhance the material's radiation-shielding capabilities, enhancing both photon and neutron attenuation and bolstering the overall performance of the glass system.

Owing to its excellent antioxidant properties, B₄C is commonly used to enhance the mechanical properties and slag corrosion resistance of MgO-C refractories. This study investigated the oxidation process of B₄C and its effects on the oxidation resistance, mechanical properties, and slag corrosion resistance of MgO-C refractories. The results revealed that at 800 ℃, B₄C in MgO-C refractories underwent significant oxidation. As the B₄C content exceeded 2%, the oxidation of MgO-C refractories was effectively suppressed. The adding of B₄C significantly improved the high-temperature bending strength and Young’s modulus of MgO-C refractories owing to the bulk expansion, pore blockage, and magnesium borate formation during B₄C oxidation. However, B₄C had minimal effect on slag corrosion resistance but significantly hindered slag penetration into the refractory interior owing to pore blockage by B₄C oxidation products.