粘弹性流体中的合性水力动力相互作用
Dae Yeon Kim1, Sachit G Nagella1, Saksham Malik1
1Department of Chemical Engineering, Stanford University, CA, USA. stakatori@stanford.edu.
Soft matter
|October 8, 2025
概括
粘弹性流体中的水力动力相互作用 (HIs) 是时间依赖的,与牛顿流体不同. 类似虫的微粒溶液表现出流量逆转和吸引力,这是由于结构记忆.
科学领域:
- 软物质物理学 软物质物理学
- 流体动力学 流体动力学
- 体科学 体科学 体科学
背景情况:
- 体粒子运动会产生干扰,导致粒子间相互作用.
- 水力动力相互作用 (HIs) 在牛顿流体中被理解得很好,但在粘弹性流体中被理解得很差.
研究的目的:
- 开发一个框架,以高的空间时间精度量化粘弹性流体中的HI.
- 为了研究HIs在虫状菌 (WLM) 溶液中的时间依赖性.
主要方法:
- 体颗粒捕获和受控转换旋转.
- 在暂时启动和停止期间直接测量时间依赖的HI.
- 分析微水力学理论,连续模型模拟和斯托克斯动力学模拟.
主要成果:
- WLM中的HI是时间依赖的,受流体结构记忆的影响.
- 观察到的流量逆转持续时间远远超过粒子运动停止后的WLM放松时间.
- 结构恢复会产生异型应力,导致流量逆转和水力动力吸引.
结论:
- 粘弹性HI与牛顿式HI的根本差异是由于其依赖时间的结构恢复.
- 当合体大小接近聚合物长度尺度时,标准连续模型可能会失败.
更多相关视频
10:28Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids
Published on: January 3, 2014
15.5K
11:38Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
8.4K
相关概念视频
Colloids and Suspensions
3.1K
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...
3.1K
Viscosity of Fluid
1.1K
Viscosity measures the resistance a fluid offers to flow and deformation. It results from internal friction between layers of fluid moving relative to one another. Dynamic viscosity, denoted by the Greek letter mu (μ), quantifies the force needed to move one fluid layer over another. For Newtonian fluids like water and air, the relationship between the shearing stress and the rate of shearing strain is linear, meaning their viscosity remains constant regardless of the applied stress.
1.1K
Newtonian Fluid: Problem Solving
865
Newtonian fluids exhibit a constant viscosity, meaning their shear stress and shear strain rate are directly proportional. This property ensures a predictable and stable response to applied forces, maintaining a linear relationship between force and flow. Examples include water, air, and light oils, consistently demonstrating this proportional behavior regardless of external conditions.
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
865
Surface Tension, Capillary Action, and Viscosity
32.7K
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...
32.7K
Colloids
20.6K
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...
20.6K
Viscosity
7.1K
When water is poured into a glass, it falls freely and quickly, whereas if honey or maple syrup is poured over a pancake, it flows slowly and sticks to the surface of the container. This difference in the flow of different kinds of liquids arises due to the fluid friction between the liquid layers and the liquid and the surrounding material. This property of fluids is called fluid viscosity. In this example, water has a lower viscosity than honey and maple syrup.
The SI unit of viscosity is...
The SI unit of viscosity is...
7.1K
