Materials Technology Reports

Evaluating eggshells as sustainable weighting agents in water-based drilling muds: A novel approach for enhanced efficiency and environmental consciousness

Anas Elhederi, Mansoor Zoveidavianpoor — Tue, 19 Nov 2024 06:16:02 +0000

This study investigates the utilization of eggshells, a renewable material, as a weighting additive in water-based drilling muds with different exploring concentrations. The primary objectives were to assess the impact of eggshells on the rheological properties of drilling muds and to determine the optimal concentration of eggshells for achieving desired density and stability, drawing comparisons with calcium carbonate (CaCO₃). Both eggshell powder (ESP) and CaCO₃ effectively increase mud weight to the target density of 8.75 ppg at 30 g. Notably, ESP exhibits favorable rheological properties at 20 g, maintaining low plastic viscosity 2.7, consistent yield points 1.1, and gel strength comparable to CaCO₃. Conversely, CaCO₃ shows signs of potential deterioration at 30 g indicated by increased viscosity to 3.5 and decreased yield point to 0.5. ESP demonstrates superior filtration performance, displaying a progressive increase in cake thickness with increasing weight 1.32 mm to 3.12 mm compared to the slower cake build-up of CaCO₃ 0.92 mm to 2.9 mm. Both additives slightly elevate mud pH, potentially enhancing overall stability.

Microwave absorption properties and mechanism of novel apatite-type materials Mn₂Gd₇.₅Ce₀.₅(SiO₄)₆O₂

Haikun Liu, Xiaoming Liu, Ning Liu, Lefu Mei — Wed, 20 Nov 2024 07:44:43 +0000

Manganese minerals possess a high intrinsic magnetic moment, making them excellent materials for microwave absorption. Rare earth elements, with their unique electronic structures and interactions between spin electrons and orbitals, can further enhance the performance of absorbing materials. In this study, we designed a novel microwave absorbing material by incorporating manganese into an apatite structure with adjustable chemical composition. The material Mn₂Gd₇.₅Ce₀.₅(SiO₄)₆O₂, exhibiting specific microwave absorption properties, was synthesized using a high-temperature solid-phase method. The results indicate that at a sample thickness of 5 mm, the absorption frequency bandwidth below −10 dB within the 2–12 GHz range reaches 1.2 GHz, with a peak absorption of −21.78 dB. Additionally, smaller particles were prepared using the sol-gel method, achieving a peak absorption of −39.75 dB. The primary absorption mechanism for both particle types is attributed to magnetic loss. This work presents a new approach to designing microwave absorbing materials and significantly contributes to expanding the range of apatite-type materials.

Energy systems and green sourced nanomaterials—A today’s outlook

Ayesha Kausar — Wed, 20 Nov 2024 08:41:11 +0000

Owing to current growing demands of environmental friendly energy devices, innumerable green materials/nanomaterials have been applied to design the desired high tech devices. Amongst energy devices, supercapacitors have been ranked distinctively for efficient energy storage competence. Principally, green nanocomposites derived from green or ecological polymers and green nanoparticles have been scrutinized for supercapacitor components. Concerning this, current review has been planned to sketch the energy storage application of green nanocomposites, predominantly for supercapacitors. In this concern, mostly synthetic green polymers (such as polyaniline, polypyrrole, etc.) and their blends with natural polymers (like chitosan) having fine biodegradability, non-toxicity, low cost, and superior device end performance have been found as the noteworthy materials. Additionally, green nanofillers like carbon nanoparticles (carbon nanotube, graphene, etc.) and metal nanoparticles have been processed with green polymers via ecological techniques, like in situ, solution, sonication, mixing, hydrothermal, exfoliation, reduction, etc., to form the anticipated energy device components. In consequence, the designed ecological nanocomposites expectedly had the advantages of low price/weight, superior mechanical/heat resilience, electron transference, capacitance, power/charge density, charge-discharge, sustainability as well as environmentally friendliness for energy related methodological systems. Incidentally, the design and performance challenges towards the application of ecological nanocomposites in energy storage devices have been conversed.