Related Experiment Video
Updated: Mar 30, 2026
11:38
Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
8.6K
Structural change and dynamics of colloidal gels under oscillatory shear flow
Jun Dong Park1, Kyung Hyun Ahn1, Seung Jong Lee1
1School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul, 151-744, Korea. ahnnet@snu.ac.kr.
Soft Matter
|November 3, 2015
Summary
This study used Brownian dynamics simulations to investigate colloidal gels under oscillatory shear. Results reveal microstructural changes from rigid to soft chain structures, altering rheological behavior across different shear amplitudes.
Area of Science:
- Colloid Science
- Rheology
- Materials Science
Background:
- Colloidal gels exhibit complex rheological behavior under shear stress.
- Understanding microstructural changes is crucial for predicting gel properties.
Purpose of the Study:
- To investigate the dynamics and rheological behavior of colloidal gels under varying oscillatory shear amplitudes.
- To elucidate the relationship between microstructural evolution and macroscopic response.
Main Methods:
- Brownian dynamics simulations were employed.
- Oscillatory shear flow with small, medium, and large amplitudes was applied.
Main Results:
- Small amplitude oscillatory shear (SAOS) maintained a rigid network with linear viscoelasticity.
- Medium amplitude oscillatory shear (MAOS) ruptured the network, showing transient behavior.
- Large amplitude oscillatory shear (LAOS) induced a soft chain structure with strain-dependent elasticity and a positive correlation between strain and bond number.
Conclusions:
- Colloidal gel rheology is dictated by shear-induced microstructural transitions.
- The transition from rigid to soft chain structures significantly impacts viscoelastic responses.
Related Concept Videos
01:17Colloids and Suspensions
3.9K
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...
3.9K
01:29The Colloidal State
142
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called...
142
01:22Problem Solving on Stress and Strain
2.1K
Stress is a quantity that describes the magnitude of a force that causes deformation, generally defined as internal force per unit area. When forces pull on an object and cause its elongation, like the stretching of an elastic band, it is called tensile stress. When forces cause the compression of an object, it is known as compressive stress. When an object is being squeezed uniformly from all sides, like a submarine in the depths of the ocean, we call this kind of stress bulk stress (or volume...
2.1K
03:22Colloids
22.1K
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 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...
22.1K
01:18Newtonian Fluid: Problem Solving
1.1K
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...
1.1K
01:27Types of Fluids
1.2K
Fluids can be classified into Newtonian and non-Newtonian fluids based on their response to shear stress. Newtonian fluids have a linear relationship between shear stress and the shear strain rate, following Newton's law of viscosity. Their viscosity remains constant regardless of the shear rate, making their behavior predictable and easier to analyze. Common examples include water, air, oil, and gasoline.
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and...
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and...
1.2K