粒度结构演变如何影响固态反应的动力学:和碳化之间相互作用的一个案例
Yaroslav A Nikiforov1, Victoria A Danilovsky2, Natalya I Baklanova1
1Institute of Solid State Chemistry and Mechanochemistry SB RAS, 18 Kutateladze st., Novosibirsk 630090, Russian Federation. nikiforov@solid.nsc.ru.
Physical chemistry chemical physics : PCCP
|January 27, 2025
概括
这项研究探讨了-碳化物反应,揭示了在高温下转向非抛物线动力学的转变. 一个新的模型通过将谷物生长与相互扩散联系起来来解释这一点,这对于高温材料至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 高温材料 高温材料
背景情况:
- 和碳化之间的固态反应形成ZrIr3,这是一种适用于高温应用的金属间化合物.
- 了解反应动力学对于优化材料特性和在高温下性能至关重要.
研究的目的:
- 为了研究和碳化之间的固态反应的动态模式.
- 开发和验证观察到的非抛物线动力学的理论模型.
- 阐明在产品阶段的谷物生长和相互扩散之间的关系.
主要方法:
- 在1500-1600°C的固态反应的实验调查.
- 开发一个包含谷物生长效应的理论模型.
- 拟议的运动模型的分析解决方案.
- 对产品层厚度和颗粒大小的微观结构分析.
主要成果:
- 在1600°C观察到从线性到非抛物线动力学的过渡.
- 拟议的模型通过考虑谷物生长成功地解释了非抛物线动力学.
- 得到了一个方程,将谷物增长和权力定律指数连接起来.
- 实验测量证实了理论预测.
结论:
- 这项研究为理解固态反应中的非抛物线动力学提供了理论框架.
- 在ZrIr3产品阶段的谷物生长显著影响反应速率.
- 这些发现有助于开发先进的高温材料.
相关概念视频
Radical Reactivity: Intramolecular vs Intermolecular
1.7K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
1.7K
Molecular and Ionic Solids
16.8K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
16.8K
Trends in Lattice Energy: Ion Size and Charge
23.7K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.7K
Ziegler–Natta Chain-Growth Polymerization: Overview
3.2K
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta...
3.2K
Structures of Solids
13.9K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
13.9K
Recrystallization: Solid–Solution Equilibria
1.0K
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
1.0K


