Related Experiment Video
Updated: May 20, 2026
10:09
Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids
Published on: March 5, 2014
Impact-activated solidification of dense suspensions via dynamic jamming fronts
Scott R Waitukaitis1, Heinrich M Jaeger
1James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA. swaitukaitis@uchicago.edu
Nature
|July 13, 2012
Summary
Dense suspensions act like liquids when gently disturbed but solidify under strong force. This study reveals impact-generated solidification, not shear thickening, explains their extraordinary ability to absorb momentum.
Area of Science:
- Physics
- Materials Science
- Fluid Dynamics
Background:
- Dense particle suspensions exhibit shear thickening, behaving like liquids when lightly perturbed but solidifying under strong forces.
- Existing models attribute shear thickening to hydrodynamic interactions or granular dilation, but these don't fully explain extreme normal stress generation under impact.
Purpose of the Study:
- To investigate the physical mechanisms behind the extraordinary impact resistance of dense particle suspensions.
- To challenge the prevailing view that shear thickening solely explains the impact behavior of these non-Newtonian fluids.
Main Methods:
- Utilized high-speed videography, embedded force sensing, and X-ray imaging to capture impact dynamics.
- Studied the deceleration of a metal rod impacting a cornflour-in-water suspension.
- Developed a quantitative model for dynamic solidification and its effects on suspension behavior.
Main Results:
- Demonstrated that impact generates a solidification front, transforming the particle matrix into a jammed region.
- Observed that this dynamic solidification leads to exceptional momentum absorption, far exceeding limits seen in shear or extension.
- Quantitatively reproduced the observed impact behavior with a novel model.
Conclusions:
- The remarkable impact resistance of dense suspensions is primarily due to impact-generated dynamic solidification, not shear thickening.
- This phenomenon creates a rapidly growing jammed region, enabling significant momentum dissipation.
- Revises the understanding of impact resistance in dense particle suspensions, highlighting a distinct solidification mechanism.
Related Concept Videos
01:16Precipitate Formation and Particle Size Control
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
01:17Colloids and Suspensions
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...
01:09Colloidal precipitates
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...
01:06Coagulation
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...
01:10Recrystallization: Solid–Solution Equilibria
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...
01:29Liquid–Solid Solutions
The process of a solid dissolving in a liquid to form a solution is governed by the solubility limit, which is the maximum amount of the solid substance, or solute, that can be dissolved in a specific volume of the liquid or solvent. As the solute dissolves, it reaches a point where no more solute can be dissolved at a given temperature - this is known as the saturation point. However, if further solute is added and it manages to dissolve, the solution becomes supersaturated. Supersaturated...