Journal of the Australian Ceramic Society最新文献

In this work, mesoporous silica particles were successfully synthesized from wheat husk ash via a precipitation method, utilizing cetyltrimethylammonium bromide (CTAB) as a structure-directing agent. The synthesized materials were characterized using XRD, FE-SEM, N₂ physisorption, zeta potential, and FTIR analyses. The introduction of CTAB during synthesis led to a significant enhancement in surface area (880.8 vs. 267.4 m²/g) and pore volume (0.879 vs. 0.194 cm³/g) compared to the template-free silica, while both adsorbents exhibited strongly negative zeta potentials confirming high colloidal stability. The equilibrium adsorption behavior of methylene blue was best described by the Langmuir isotherm, confirming monolayer adsorption with a maximum capacity (q_max) of 110.3 mg/g for CT-MPSi, and thermodynamic analysis indicated spontaneous adsorption (ΔG° = −26.6 kJ mol^− 1). FTIR analysis confirmed MB retention on both surfaces, with markedly stronger dye uptake on CT-MPSi, and the material retained 81.7% removal efficiency after five consecutive cycles. These results show that CTAB-templated mesoporous silica derived from wheat husk ash can serve as a viable and low-cost adsorbent for cationic dye removal from aqueous media.

The development of advanced biomaterials for dental restoration has gained significant attention due to the need for durable and bioactive implant materials. Biofilm formation after implantation remains a major clinical challenge. This study explores tannic acid-loaded hydroxyapatite-yttria-stabilized zirconia as a novel composite for dental applications. Hydroxyapatite (HA) offers excellent biocompatibility, YSZ provides stability in the biological medium, and tannic acid (TA), a natural polyphenol, introduces antimicrobial functionality to help prevent infection. Structural, mechanical, and biological characteristics of the fabricated scaffolds were analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and in vitro biological studies. The analyses confirmed the successful fabrication of TA-loaded HA–YSZ scaffolds. Antibacterial studies showed a significant reduction (~ 99%) in Staphylococcus aureus (S. aureus) growth due to TA incorporation. Cytocompatibility tests confirmed that the material is non-toxic. Bioactivity evaluation in simulated body fluid (SBF) demonstrated an appropriate balance between bioactivity and bio inertness. Overall, the TA-modified HA–YSZ system shows strong potential as a multifunctional material for dental implant applications.

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Magnetic iron oxide (Fe₃O₄) nanoparticles are widely recognized for their potential in environmental remediation owing to their excellent magnetic properties, chemical stability, and recyclability. However, their standalone photocatalytic performance remains limited due to rapid charge carrier recombination, particle agglomeration, and low surface activity. In this study, Fe₃O₄ was coupled with graphitic carbon nitride (g-C₃N₄) to form a Fe₃O₄/g-C₃N₄ ceramics nanocomposite, synthesized through a high-energy ball-milling process. XRD, FTIR, XPS, BET, Raman measurements were performed to demonstrate that Fe₃O₄ and g-C₃N₄ were successfully integrated to make a stable heterojunction. The incorporation of Fe₃O₄ reduced the bandgap energy of g-C₃N₄ from 2.81 eV to 2.12 eV, enhancing visible-light absorption. BET analysis revealed a surface area of 49.79 m²/g and mesoporous structure, supporting improved adsorption and charge transfer. Raman shift of T_12g and E_g modes also confirmed that there was a high interfacial interaction between Fe₃O₄ and g-C₃N₄. Under visible-light irradiation, the Fe₃O/g-C3N ceramics nanocomposite achieved 95% degradation of malachite green (MG) within 60 min. The addition of H2O2 further promoted degradation through a photo-Fenton-like mechanism. Scavenger experiments also confirmed that ^•OH and h⁺ were the main reactive species, which validated the synergistic photocatalytic/photo-Fenton pathway. Furthermore, kinetic analysis followed pseudo-first-order behavior consistent with the Langmuir–Hinshelwood model. The material also demonstrated excellent stability, magnetic separability, and reusability across multiple cycles. The novelty of this work lies in the development of a magnetically recoverable Fe₃O₄/g-C₃N₄ ceramic nanocomposite via a green, solvent-free ball-milling approach, integrating visible-light photocatalysis with Fenton-like activity for sustainable wastewater treatment.

This study investigates the feasibility of using rice husk ash (RHA) as a sustainable silica source for synthesizing sodium waterglass which serves as an activator in geopolymer composites based on municipal solid waste incineration fly ash (MFA). Six different mixes were prepared using RHA-derived activators and without activators. The activation moduli (Ms) ranged from 0.0 to 1.10. The mixes were evaluated for compressive strength, density, water absorption, porosity, capillary water absorption, and microstructural characteristics using scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). To compare the mechanical strength, total porosity, and water absorption of mixes, a one-way analysis of variance (ANOVA) was conducted at a significance level of 5%. The RHA30 mix (Ms = 1.0) obtained the highest compressive strength of 31.56 MPa at 28 days, compared to just 7.19 MPa for the NaOH-only mix (Ms = 0.0). Bulk density increased from 2265 kg/m³ (MFA-RHA0) to a peak of 2861 kg/m³ (MFA-RHA30) while total porosity and water absorption decreased to 16.83% and 4.51%, respectively. Capillary water absorption was also reduced with the sorptivity coefficient (k) dropping by 15.46% in the optimal RHA mix. Microstructural analyses confirmed the formation of dense N/C-A-S-H and C-A-S-H gels. XRD and FTIR results indicated successful polymerization and development of amorphous aluminosilicate networks with spectra shifts confirming improved cross-linking.

The control of concrete properties depends on the cement hydration process and the formation of hydrated phases. The increase of hydrated phases and the increase of hydration kinetics increase the mechanical properties of cement. Additives can affect the final properties of concrete. In this research, the properties of MgO-PEG nanocomposite on the mechanical properties of cement paste were investigated. The formation of MgO-PEG nanocomposite was investigated by XRD, DTA characterization techniques. Then different percentages of MgO-PEG nanocomposite were added to the cement paste and its strength and heat of hydration were investigated. The compressive strength increased by 89.76%, 106.02%, 98.87%, and 99.45% for the samples containing 0, 1, 3, and 5 wt% MgO-PEG nanocomposites, respectively. The results demonstrated that PEG alone may decrease compressive strength and hydration-related performance due to increased water absorption, whereas forming a MgO–PEG composite effectively counteracts this issue by improving hydration and microstructural densification.

This study investigates the reuse of İzmit Gulf bottom sludge as a silica substitute in black opaque wall tile glazes. The sludge, containing 44.64 wt% SiO₂ and 7.47 wt% Fe₂O₃, was incorporated at 25–100 wt% replacement rates. Viscosity measurements showed that higher sludge levels significantly increased viscosity from 460 to 920 mPa·s. Thermal analyses revealed that sintering and softening temperatures rose from 734 °C to 798 °C (STD) to 798 °C and 832 °C (S4), demonstrating improved refractory behavior. Microhardness values peaked at ~ 720 Hv in the S1 composition (25 wt% sludge), exceeding both the reference glaze (~ 650 Hv) and higher sludge samples, which showed reduced hardness due to porosity. Gloss decreased progressively from 92 (STD) to 75 (S4), while color parameters remained stable. Leaching tests confirmed that all heavy metals stayed within regulatory limits, although chromium release increased to 0.03 mg/L in S4 but remained below the 0.05 mg/L threshold. Therefore, S1 composition offered the most balanced performance, combining improved hardness, acceptable gloss, and environmental compliance. The findings demonstrate that İzmit Gulf sludge can be valorized as a sustainable glaze raw material when used in controlled proportions, supporting resource conservation and waste minimization in ceramic production.

This study presents the design, fabrication, and performance evaluation of novel AA7075-based hybrid metal matrix composites (HMMCs) reinforced with fly ash (FA) and boron carbide (B₄C), developed via an ultrasonic-assisted stir casting route. The dual-reinforcement strategy leverages the low density and thermal insulating nature of FA, alongside the exceptional hardness of B4C, to achieve superior mechanical and tribological properties while promoting sustainability through the utilization of industrial waste. Comprehensive characterization—including optical, SEM, EDS, and XRD—revealed uniform reinforcement dispersion, strong interfacial bonding, and the formation of strengthening phases such as Al₂O₃, Al₂CuMg, B₄C, and MgZn₂ within the Al matrix. The incorporation of reinforcements led to a progressive reduction in density, accompanied by an increase in porosity at higher loadings, due to clustering and reduced wettability. Notably, the composite with 2 wt.% FA and 6 wt.% B₄C demonstrated the highest hardness and wear resistance, with significant improvements over monolithic AA7075. Wear behavior was systematically studied under varying sliding distances (up to 5000 m) and applied pressures (0.25–1.00 MPa). The wear rate decreased with distance due to the formation of a stable, mechanically mixed layer, while hybrid composites exhibited a delayed transition to severe wear, higher seizure resistance, and reduced thermal softening effects.

Calcium borate has been employed for various purposes, including fire resistance enhancement, lubrication, and coating applications. This research aimed to analyze calcium borate synthesis through a solid-state reaction, which includes various parameters such as composition, temperature, and time. To achieve this, a selected composition was subjected to thermal analysis by DTA/TG, and the decomposition behavior of CaCO₃ and H₃BO₃ was determined. Additionally, the solid-state reaction temperature was defined as 900 °C. Six compositions were designed based on the CaO-B₂O₃ binary phase diagram, using calcium carbonate and boric acid as starting materials. The synthesis of calcium borate was carried out at 900 °C for 3 h. X-ray diffraction (XRD) analysis performed to determine phase analysis of solid stated calcium borate composition and detected Ca₂B₂O₅, Ca₂B₂O₄, CaB₄O₇. Scanning electron microscopy (SEM) were then used to investigate the morphological properties of the produced powder. An increase in the amount of boron content, solid-state morphology transforms cluster-enlarged particles, depending on the existence of CaB₄O₇. Stretching of the bonds was investigated using FTIR, and therefore, three different calcium borate phases, which are Ca₂B₂O₅, Ca₂B₂O₄, and CaB₄O₇, were found. Therefore, different calcium borate forms were produced via solid state reaction, and the increase in boron amount encouraged the formation of CaB₄O₇.