Related Experiment Video
Updated: Jun 9, 2025
09:08
Measuring Material Microstructure Under Flow Using 1-2 Plane Flow-Small Angle Neutron Scattering
Published on: February 6, 2014
14.3K
Poiseuille and extensional flow small-angle scattering for developing structure-rheology relationships in soft matter
Avanish Bharati1,2, Steven D Hudson3, Katie M Weigandt1
1Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, USA.
Current Opinion in Colloid & Interface Science
|October 23, 2024
Summary
This review highlights advances in rheoscattering beyond simple shear, focusing on Poiseuille and extensional flow small-angle scattering. Recent experiments reveal structure-function relationships in diverse soft materials.
Area of Science:
- Soft matter physics
- Materials science
- Scattering techniques
Background:
- The field of rheoscattering has expanded significantly, encompassing diverse materials, flow types, and analytical methods.
- There is a growing need to understand material behavior under complex flow conditions beyond simple shear.
Purpose of the Study:
- To review recent developments in rheoscattering that extend beyond traditional shear measurements.
- To focus on advancements in Poiseuille flow and extensional flow small-angle scattering.
- To highlight the establishment of structure-function relationships in various soft materials.
Main Methods:
- Small-angle scattering (SAS) techniques applied to soft materials under flow.
- Analysis of data from Poiseuille flow (pressure-driven) and extensional flow experiments.
- Correlation of scattering data with material properties and macroscopic behavior.
Main Results:
- Recent rheoscattering studies have successfully employed Poiseuille and extensional flow geometries.
- These studies have yielded crucial insights into the microstructural evolution of soft materials during flow.
- Emerging structure-function relationships are being established for a broad range of soft materials.
Conclusions:
- Rheoscattering, particularly using Poiseuille and extensional flow, is a powerful tool for characterizing soft materials.
- Understanding material response under complex flows is key to developing advanced soft materials.
- The development of structure-function relationships is advancing rapidly in the field.
Related Concept Videos
01:22Couette Flow
214
Couette flow represents the flow of fluid between two parallel plates, with one plate fixed and the other moving with a constant velocity. This configuration allows for a simplified analysis using the Navier-Stokes equations, which govern fluid motion under conditions of viscosity and incompressibility. For Couette flow, the assumptions include a steady, laminar, incompressible flow with a zero-pressure gradient in the flow direction. This flow type is beneficial for understanding shear-driven...
214
01:19Viscosity of Fluid
353
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.
353
01:10Poiseuille's Law and Reynolds Number
6.4K
Any fluid in a horizontal tube can flow due to pressure differences—fluid flows from high to low pressure. The flow rate (Q) is the ratio of pressure difference and resistance through a horizontal tube. The greater the pressure difference, the higher the flow rate. The flow resistance is expressed as:
6.4K
01:11Pressure Variation in a Fluid at Rest
222
In a fluid at rest, the pressure at any point beneath the fluid surface depends solely on the depth, not on the container's shape or size. This principle, known as hydrostatic pressure, arises because, in stationary fluids, there is no acceleration, meaning the forces within the fluid balance out. Only vertical forces, caused by the weight of the fluid above, contribute to pressure changes with depth.
When measuring pressure at two different levels within the fluid, the difference in...
When measuring pressure at two different levels within the fluid, the difference in...
222
01:20Elastic Strain Energy for Shearing Stresses
165
As discussed in previous lessons, strain energy in a material is the energy stored when it is elastically deformed, a concept crucial in materials science and mechanical engineering. This energy results from the internal work done against the cohesive forces within the material. When a material undergoes shearing stress and corresponding shearing strain, the strain energy density, which is the energy stored per unit volume, is calculated. Within the elastic limit, where the stress is...
165
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
251
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
251