低刺激防止颗粒组件的结晶,而颗粒组件受到高频振动的影响
Sara AlMahri1,2, Ivan Grega1, Angkur J D Shaikeea1
1Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom.
概括
高频振动通过创建边界层,令人惊地阻碍了粒子组合中的晶体形成. 这项研究揭示了如何克服可扩展的微/宏晶体组件的这种效应.
科学领域:
- 材料科学 材料科学 材料科学
- 物理 物理学 物理
- 化学工程是化学工程的重要组成部分.
背景情况:
- 振动结晶是一种可扩展的方法,用于组装微/宏晶体.
- 由于高频率的过度兴奋,被认为存在最佳频率.
研究的目的:
- 为了研究高频振动对粒子组合结晶的反直觉效应.
- 阐明在高频率下粒子低刺激的基本机制.
主要方法:
- 被打断的X射线计算机断层扫描.
- 高速摄影摄影技术的使用.
- 离散元素模拟的模拟.
主要成果:
- 高频振动导致粒子过度激发,而不是过度激发.
- 一个流体化的边界层形成,防止动量转移到粒子质量.
- 这种低刺激抑制了结晶所需的粒子重新排列.
结论:
- 最佳频率概念是基于对高频振动效应的误解.
- 流化边界层是抑制高频结晶的关键机制.
- 抑制流化的一种策略使得在高频振动下结晶成为可能.
相关概念视频
Recrystallization: Solid–Solution Equilibria
1.1K
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...
1.1K
Crystal Growth: Principles of Crystallization
2.1K
Crystallization is a phase transformation process in which crystals are precipitated from a supersaturated solution or formed from other sources. During crystallization, atoms or molecules arrange themselves into a well-defined, rigid crystal lattice to minimize energy.
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
2.1K
Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K
Unsoundness of Aggregate due to Volume Change
137
Unsoundness in aggregates due to volume changes is primarily caused by the physical alterations aggregates undergo, such as freezing and thawing, thermal changes, and wetting and drying. Unsound aggregates, when subjected to these changes, result in volume change upon disintegration. This, in turn, contributes to the deterioration of concrete, including scaling, pop-outs, and cracking. Particular types of aggregates, such as porous flints, cherts, and those containing clay minerals, are...
137
Precipitation Processes
490
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...
490
Colloidal precipitates
625
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
625


