What are the current methods being used for the synthesis of magnetite nanoparticles ?5 answersCurrent methods for synthesizing magnetite nanoparticles include Hydrothermal synthesis, Co-precipitation technique, Sol-Gel process, controlled precipitation method, and microwave-assisted hydrothermal method. Hydrothermal synthesis involves using FeCl2·4H2O and FeCl3·6H2O precursors with NaOH as the hydrolysis agent. Co-precipitation and microwave-assisted hydrothermal methods are utilized for incorporating antitumoral drugs like usnic acid into magnetite nanoparticles, enhancing control over properties. The controlled precipitation method, using iron chloride, iron sulfate, and ammonium hydroxide, produces magnetite nanoparticles without requiring an inert atmosphere, demonstrating efficiency in synthesis. These methods play a crucial role in determining the size, shape, and magnetic properties of the nanoparticles, impacting their applications in various fields such as biomedicine, renewable energy, and electronics.
What are the potential applications of magnetite nanoparticles in material science?5 answersMagnetite nanoparticles have potential applications in material science, including medicine, cancer therapy and diagnostics, biosensing, and magnetic separation. They are extensively used in various bioapplications due to their biocompatibility, high saturation magnetization, chemical stability, large surface area, and easy functionalization. Additionally, magnetite nanoparticles impregnated into pyrolyzed coconut coir have been found to be suitable as an adept adsorption material for water softening applications. The synthesis parameters of nanostructured iron oxides can be controlled to obtain magnetite nanoparticles with suitable properties for biomedical applications, such as acceptable hydrodynamic diameter, high saturation magnetization, and reduced toxicity. These nanoparticles have been shown to possess minor intrinsic toxicity and could be well-suited for biomedical applications.
How to use magnetic nanoparticles?3 answersMagnetic nanoparticles can be used in various applications such as drug delivery, magnetic hyperthermia, magnetic resonance imaging (MRI), magnetic particle imaging, biosensors, tissue engineering, biosynthesis, catalysis, electronic and microwave-absorbing materials, and environmental treatment. They have high surface area, size-dependent superparamagnetic properties, precision tunability, and easy surface modification, making them versatile for different purposes. The chemical coprecipitation method is commonly used for their preparation due to its simplicity, low cost, and easily-controlled operating conditions. Magnetic nanoparticles can be coated with human serum albumin or polyethylene glycol to enhance biocompatibility and minimize potential toxicity when used in vivo. They can interact with lipid membranes, potentially leading to the appearance of conducting pores and increasing the integral conductivity of the membranes. In environmental science and engineering, magnetic nanoparticles have been used for the purification of whey, removal of heavy toxic metals, and photocatalytic degradation of pollutants in water.
What are the different mechanisms of nanocrystal nucleation and growth?5 answersNanocrystal nucleation and growth can occur through different mechanisms. In the case of zirconia nanocrystals, nucleation is believed to occur through a second-order process, where small amorphous particles act as the source of nanocrystal growth. Gold nanocrystal growth involves the formation of poorly crystalline nanoparticles, which then undergo nanocrystallization through multiple exchanges of matter between a crystalline core and a disordered shell. The formation of nanocrystals of the charge transfer compound perylene:7,7′,8,8′-tetracyanoquinodimethane (TCNQ) can exhibit non-classical nucleation, with solid particles forming immediately and longer-range order appearing later. The nucleation and growth of platinum nanocrystals involve the formation and growth of amorphous clusters, followed by crystallization and growth of clusters, and the ripening of nanocrystals. These different mechanisms of nucleation and growth provide insights into the processes involved in the formation and evolution of nanocrystals.
What is the size of maghemite particle?5 answersThe size of maghemite particles varies depending on the synthesis method and conditions. In one study, the mean physical size of the nanoparticles was found to be 9.5 nm. Another study reported maghemite particles with sizes in the range of 2.5-5.6 nm. Additionally, a patent mentioned magnetite particles with a diameter between 10 and 50 nm. Furthermore, porous crystals of maghemite were obtained with inner grain sizes of 64±6 nm and 84±8 nm. These findings indicate that maghemite particles can have sizes ranging from a few nanometers to tens of nanometers.
What is the mechanism of the increase in particle size?3 answersThe mechanism of the increase in particle size varies depending on the context. In the study by Darcovich, size enlargement processes such as agglomeration by tumbling, pressure compaction, and extrusion methods, heat reaction, fusion, and drying methods, and agglomeration from liquid suspensions by competitive wetting are discussed as mechanisms for bringing particles together into larger masses. In the study by Vengrenovich et al., the mechanism of particle growth is proposed to be controlled by both volume diffusion and the rate of chemical bond formation on the particle surface, as observed in the Ostwald ripening process. In the study by Wang et al., it is suggested that the increase in particle size in CeO2 nanocrystals is a result of pressure-induced effects on surface energy, Young's modulus, and Poisson's ratio.