温度对磁石纳米颗粒通过共沉降方法合成的影响
Frederico Vieira Gutierrez1, Iara Souza Lima2, Anna De Falco3
1Physics Department, Pontifical Catholic University of Rio de Janeiro, Rua Marques de São Vicente, 22451-900, Rio de Janeiro, Brazil.
Heliyon
|February 23, 2024
概括
合成温度影响磁性纳米粒子的特性. 这项研究证实了磁纳米颗粒的超偏磁性行为,这对于医疗应用至关重要,其特征通过多次分析来验证.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术 纳米技术
- 生物医学工程 生物医学工程
背景情况:
- 磁性纳米粒子,特别是磁铁 (Fe3O4),由于其超偏磁性特性,显示出对医疗应用的希望.
- 共同沉技术为生产这些纳米颗粒提供了一种具有成本效益的方法.
- 控制合成参数是为特定应用量身定制纳米粒子特征的关键.
研究的目的:
- 研究合成温度对磁石纳米粒子物理化学性质的影响.
- 描述合成纳米粒子的磁性行为和结构属性.
- 评估这些纳米粒子对于潜在的生物医学用途的适用性.
主要方法:
- 用于在不同温度下进行纳米粒子合成的共同沉方法.
- 磁性分析包括磁化曲线和零场冷却/场冷却 (ZFC-FC) 测量.
- 使用X射线衍射 (XRD),拉曼光谱和传输电子显微镜 (TEM) 的结构和形态表征.
主要成果:
- 合成的纳米粒子在室温下表现出超偏磁性行为,通过磁化曲线和ZFC-FC分析得到证实.
- 拉曼光谱识别了特征性的磁石相带,验证了材料的组成.
- 多种表征技术证实了磁纳米颗粒的发展,其平均直径在数十纳米范围内.
- 发现阻塞温度低于环境温度,与超对磁性相一致.
结论:
- 合成温度显著影响磁铁纳米颗粒的物理化学特性.
- 生产的纳米颗粒显示出适合生物医学应用的超偏磁特性.
- 这项研究验证了用于生产可调节磁纳米粒子的共沉方法.
相关概念视频
Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
Precipitation Processes
447
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
447
Precipitation and Co-precipitation
1.8K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
1.8K
Temperature Dependence on Reaction Rate
81.7K
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
81.7K
Types of Coprecipitation
615
Coprecipitation is the contamination of a precipitate by otherwise soluble species and occurs via different processes. In colloidal precipitates, coprecipitation occurs via surface adsorption. For instance, barium sulfate has a primary layer of adsorbed barium ions and a secondary layer of nitrate counterions. This results in contamination of the precipitate by barium nitrate.
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...
615
Precipitate Formation and Particle Size Control
779
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
779


