Journal of the Australian Ceramic Society最新文献

In this study, three different ilmenite-limonite (ILC) concretes were modeled in terms of determining the effect of filler type and filler size on the enhancement of radiation shielding properties in the 0.142–1.33 MeV gamma-ray energy range. Accordingly, ILC concrete, micro (50 µm) and nano (50 nm) WO₃, and micro (50 µm) and nano (50 nm) PbO filler added ILC samples were modeled. MCNPX simulations of micro- and nano-sized particles inside of the ILC sample were performed using lattice (LAT) and universe (U) features of MCNPX (version 2.7.0) code. The greatest increase in mass attenuation coefficient was reported from micro-PbO to nano-PbO filler as 7.88% at 0.142 MeV energy value. The study’s findings indicated that decreasing the particle size of the additive material decreases the mean free path and so increases the quantity of gamma radiation interacting per unit distance. Although we validated the consistency of our input against the standard NIST database, several points, such as experimental investigations of nanoparticles in ILC concrete, nanoparticle distributions, and the effect of this distribution on overall shielding enhancement, should be investigated further.

Eggshells have been reported to generate huge tons of waste globally. Various uses of eggshells are widely reported in the literature in terms of dietary supplements, filler in bones, etc. through their extraction as a Ca source. In this study, 900 °C was adopted for CaO and CaCO₃ formation from the eggshell. This heated eggshell powder was further reacted with hydrofluoric acid (HF) aqueous solution to prepare CaF₂. This CaF₂ was first tested for antibacterial activity against E. coli, which indicated that CaF₂ derived from eggshell was effective as an antibacterial. By incorporating CaF₂ (5%, 10%, and 15% by wt.) into cement mortar, it was found that the mortar composites showed antibacterial activity. Furthermore, photocatalytic activity was monitored using the degradation of the dye solution. All the mortar composites have demonstrated photocatalytic properties.

Zeolites, a type of microporous hydrated aluminosilicate minerals, are a popular candidate in the field of catalysis due to their high thermal stability as well as their good absorption capability. In this study, Vietnamese kaolin was employed as an unexpensive and abundant substitute for the synthesis of zeolite A. Nickel as well as several metallic were also incorporated in zeolite via ion exchange method. Ten-percent Ni/zeolite catalyst was studied the carbon dioxide (CO₂) conversion to methane (CH₄) in a fixed-bed tubular reactor. We observed that the highest catalytic activity of 55.2% CO₂ conversion and 92.7% CH₄ selectivity was obtained at 350 °C, 1 atm, H₂:CO₂ ratio of 4:1, and gas hourly space velocity (GHSV) of 9000 mL g⁻¹ h⁻¹. These results show a promising pathway of modifying Vietnamese natural kaolin as an economical and efficient alternative material for the preparation of zeolite A together with its catalytic application.

Bioceramics are a fast-growing materials group, which are widely used in orthopedics, maxillofacial, dental, and reconstructive surgeries. They are produced using raw materials either from synthetic or natural sources. As naturally originated resources, the bones of sheep and cows are used after converting to calcium phosphates. Human-originated sources in the past were obtained from human cadaver bones, however now-a-days this has been discontinued. On the other hand, the “golden standard” in the reconstruction surgery has been using patients own bones, -i.e., autogenous bones, which heal better than other alternatives. Besides natural products, synthetic materials are produced from a range of inorganic raw and natural materials based on marine sources, such as corals, and other marine-derived materials (i.e., seashells, nacre). These are used to produce bioceramics and hence implants, devices, and bone grafts. Although during the last four decades a number of excellent books and book chapters have been published, no comprehensive review has been yet reported to cover the available marine materials and to indicate the related work and corresponding references to allow for both medical and ceramic scientists to access directly and open new avenues for further research on marine structures and their applications in orthopedic, maxillofacial, and reconstructive surgery areas. Hence, this review covers the general marine structures, their locations and availability in different countries and, current research on production methods of these unique structures that are difficult to fabricate synthetically. The authors are confident that this comprehensive review will be an excellent source not only for the ceramists, but also for the medical scientists.

Sm_0.5Sr_0.5Zr_1−xNi_xO_3.25−x (x = 0, 0.1, 0.3, 0.5, 0.7) oxides were synthesized via the solid-state reaction method. The structural and morphological properties were studied by X-ray diffraction, a laser size analyzer, and scanning electron microscopy. The Sm_0.5Sr_0.5Zr_1−xNi_xO_3.25−x (x = 0, 0.1, 0.3, 0.5, 0.7) cathodes were symmetrically deposited on a Ce_0,8Sm_0,17La_0.03O_1,9 electrolyte with the spin-coating method, and the area-specific resistance values were determined by electrochemical impedance spectroscopy. Results show that co-doping with the appropriate amount of nickel affects the structural and electrical properties of the cathode compound.

Thin films of ZnO, with distinct thicknesses, were deposited on soda-lime glass substrates by sol–gel spin-coating as a cost-effective method without any evacuation facilities. The nanocrystalline structure of the deposited films was indexed by the atomic force microscope and X-ray diffraction techniques. The average grain size increases with the increase of the film thickness and annealing temperature. The energy-dispersive X-ray technique has been used to check the atomic ratios of Zn and O with the film thickness and heat treatment for homogeneous ZnO films. ZnO films show elevated transmission in the visible spectrum as a transparent semiconductor material. Optical constants, like absorption coefficient, optical band gap, and refractive index, were obtained by the Swanepoel method. All thin film samples were applied for photodegradation of reactive orange 96 (RO96) to evaluate the effect of thickness and annealing temperature on the ZnO film’s photocatalytic activity. ZnO 4L (400 °C, 3 h) film possesses the highest rate of photodegradation about 0.1 min⁻¹ for RO96 with high stability and reusability.