具有低度有吸引力的固体颗粒的合体系统的粘弹性特性:一篇综述,新结果和解释
Philippe Martinoty1, Antoni Sánchez-Ferrer2
1Institut Charles Sadron, UPR 22, CNRS/UDS, 23 rue du Loess, BP 84047, F-67034 Strasbourg, France.
Advances in colloid and interface science
|November 14, 2024
概括
这项研究研究了在低度下具有弱吸引力的体系统,揭示了它们的行为是"集群流体". 它们的固体状特性源于可逆网络结构,与传统模型不同.
科学领域:
- 体科学是关于体的科学.
- 类风病学 类风病学 类风病学
- 软物质物理学 软物质物理学
背景情况:
- 具有短距离吸引力的体系统的低体积分数 (φ) 模式仍在争论中,提出了透,扩散有限体聚合 (DLCA) 和干扰等概念.
- 现有的模型,如模式合理论 (MCT),对于高φ模式是很成熟的,但对于低φ系统则不那么成熟.
研究的目的:
- 分析具有在低体积分数的短距离吸引力的合体系统的粘弹性和结构.
- 重新评估特定有吸引力的系统 (碳黑,PMMA/PS,器官凝聚器) 的行为,并对它们的反应进行分类.
主要方法:
- 风湿学测量以研究粘弹性特性 (弹性模量G'和粘度模量G").
- 对结构变化和粒子间相互作用 (1-15 k B T) 的分析.
- 实验数据与理论概念 (如干扰和集群形成) 的比较.
主要成果:
- 在低φ的三个不同的有吸引力的合体系统被确定为"集群流体".
- 在低频率下,类似固体的粘弹性响应 (G'>G") 归因于可逆网络结构.
- 由于微弱的粒子间相互作用,在高频率下观察到类似液体的状态.
- 两个模块的主曲线描述了这些集群流体,使其能够进行分类.
结论:
- 在低体积分数的有吸引力的体系统可以表现出集群流体的行为.
- 观察到的固体状反应是可逆网络形成的结果,而不是永久的聚合.
- 基于这些系统的粘弹性主曲线,提出了对这些系统的统一分类框架.
相关概念视频
01:17Colloids and Suspensions
1.7K
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles visible to the naked eye or seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. The suspended particles in a suspension settle out after some time of mixing. The separation of particles from a suspension is...
1.7K
03:22Colloids
17.4K
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...
17.4K
01:09Colloidal precipitates
517
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...
517
01:06Coagulation
273
Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...
273
01:24Van der Waals Interactions
63.5K
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.
63.5K
02:57Surface Tension, Capillary Action, and Viscosity
27.5K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
27.5K