Home > Press > Stirred, not shaken: Physicists gain more particle control
Abstract:
Cornell physicists can now precisely control how particles in viscous liquids swirl, twirl and whirl. Think of coffee and adding cream -- and gaining control of the particles in the cream. Understanding this concept could allow chemists, physicists and engineers to better detect molecules, control the mixture of nanoscale particles and enhance self-assembly in solutions.
Brian Leahy, Cornell doctoral student in the field of physics, presented "Revisiting Taylor Dispersion: Differential Enhancement of Rotational and Translational Diffusion Under Oscillatory Shear" at the American Physical Society meeting, Baltimore, March 18. His co-researchers include: Xiang Cheng, physics postdoctoral researcher; Itai Cohen, professor of physics; and Desmond Ong '11.
If you stir, diffusion -- the random jostling of small particles from thermal energy -- is enhanced. This enhancement is called Taylor dispersion. "Stirring transports the cream through the coffee and also enhances diffusion of the cream particles," said Leahy.
Using 3-D imaging microscopes, the physicists can now also see the orientation of oblong particles in a viscous fluid, providing the ability to measure the individual particle rotation rates for the first time.
"By adding shear and adjusting the flow, particles can not only be oriented but their rotational diffusion can also change," said Leahy.
In a fluid, oblong particles that are small enough can change their orientation due to rotational diffusion that arises when fluid molecules kick the particles in random directions. When the particle-laden fluid is rubbed between two oscillating plates, the oblong particles also rotate end-on-end in what is known as a Jeffery's orbit.
The researchers showed that the combination of rotational diffusion and Jeffery orbits has an effect that is bigger than the so-called "sum of the parts," so that the particles change their orientation faster than either mechanism alone.
While this is basic, physical research, understanding these concepts could lead to opportunities in other fields, said Cohen: improved self-assembly of specially shaped particles, designer materials, or producing liquids with directional dependence that flow easily.
Leahy is supported by a National Defense Science and Engineering Graduate Fellowship.
####
For more information, please click here
Contacts:
Media Contact:
John Carberry
(607) 255-5553
Cornell Chronicle:
Blaine Friedlander
(607) 254-8093
Copyright © Cornell University
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related News Press |
Physics
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024
News and information
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Imaging
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Govt.-Legislation/Regulation/Funding/Policy
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Self Assembly
Liquid crystal templated chiral nanomaterials October 14th, 2022
Nanoclusters self-organize into centimeter-scale hierarchical assemblies April 22nd, 2022
Atom by atom: building precise smaller nanoparticles with templates March 4th, 2022
Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022
Discoveries
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
New micromaterial releases nanoparticles that selectively destroy cancer cells April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
Materials/Metamaterials/Magnetoresistance
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Focused ion beam technology: A single tool for a wide range of applications January 12th, 2024
Announcements
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Tools
Ferroelectrically modulate the Fermi level of graphene oxide to enhance SERS response November 3rd, 2023
The USTC realizes In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors November 3rd, 2023
Military
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
New chip opens door to AI computing at light speed February 16th, 2024
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||