Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Flowing Structures in Soft Crystals

Intriguing structures formed by tiny particles floating in liquids. (Copyright: Vienna University of Technology)
Intriguing structures formed by tiny particles floating in liquids. (Copyright: Vienna University of Technology)

Abstract:
A liquid does not have to be a disordered bunch of particles: A team of researchers at Vienna University of Technology (TU Vienna) and the University of Vienna has discovered intriguing structures formed by tiny particles floating in liquids. Under mechanical strain, particle clusters in liquids can spontaneously form strings and dramatically alter the properties of the liquid.

Flowing Structures in Soft Crystals

Vienna, Austria | Posted on August 8th, 2011

What is common to blood, ink and gruel? They are all liquids in which tiny particles are suspended - so called "colloids". In some of these liquids, the particles form groups (clusters), which form regular structures, much like atoms in a crystal. A team of researchers from TU Vienna and Vienna University has now managed to study the remarkable properties of these crystal-like substances in computer simulations. Under mechanical strain, the crystalline pattern can change into a different structure, or it can vanish completely. The researchers anticipate a broad range of practical applications for these effects. The results of their calculations have now been published in the scientific journal "Physical Review Letters".

Regular Structures in Liquids
If small particles accumulate, they can form clusters. Within a cluster, the particles may overlap and mingle, similar to a densely packed shoal of eels, gliding past each other. Remarkably, these clusters are not situated at random positions, but they spontaneously form a regular structure - a "cluster crystal". The distance between two neighboring clusters is constant. "Increasing the density of particles adds more and more particles to each cluster - but the distance between them stays the same", says Arash Nikoubashman, PhD-student at TU Vienna. He made the calculations together with Professor Gerhard Kahl (Institute for Theoretical Physics, TU Vienna) and Professor Christos Likos (University of Vienna).

Crystal Structure Turning into Strings
"Previous results had already led us to believe that these particles could exhibit strange behavior under certain external conditions", the physicists explain. And their hopes were not unfounded: in computer simulations they managed to calculate how the crystal-like structure behaves under mechanical strain that causes shears stress - which means that surfaces within the liquid are shifted relative to each other. At first, the crystal structure starts to melt, the connections between the clusters are broken. From these molten particle clusters, a new regular order starts to emerge spontaneously. Long, straight strings of particle are formed, neatly aligned in parallel.

Thin and Thick
While these strings are created, the liquid gets thinner, its viscosity decreases. This is due to the strings being able to slide relative to one another. If the material is subject to even more strain, the strings break up too, a "molten" unstructured ensemble of particle clusters remains, and the viscosity of the liquid increases again. More and more particles are washed away from their original positions and inhibit the flow. This behavior is the same for all kinds of cluster crystals. With a simple theoretical model, the critical strain, at which the ordered structure vanishes completely, can be predicted very accurately.

Under shear strain, crystals made of soft, penetrable particles can exhibit new kinds of self-organization. Geometric structures emerge, governed by the kind of forces acting between the particles. This research in the field of "soft matter" in the micro- and nanometer regime is not only interesting from a theoretical point of view. These materials play an important role in our everyday life - such as blood or large biopolymers like DNA. They are important in biotechnology, and also in petrochemistry and pharmacology - wherever tailor-made nano materials are being used. A liquid which can change its viscosity under mechanical stress promises a broad spectrum of possible applications - ranging from vibration dampers to protective clothing.

####

For more information, please click here

Contacts:
Scientific contacts
Univ.-Prof. Dipl.-Ing. Dr. Christos Likos
Computational Physics
University of Vienna
1090 Wien, Sensengasse 8
T +43-1-4277-732 30


Arash Nikoubashman
Vienna University of Technology
Wiedner Hauptstraße 8-10
T +43-1-58801-136 31


Press contact
Mag. Veronika Schallhart
Public Relations
University of Vienna
1010 Vienna, Dr.-Karl-Lueger-Ring 1
T +43-1-4277-175 30
M +43-664-60277-175 30

Copyright © University of Vienna

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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Discoveries

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

Materials/Metamaterials

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 2017

Manchester scientists tie the tightest knot ever achieved January 13th, 2017

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

Announcements

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

Textiles/Clothing

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

Engineers develop new magnetic ink to print self-healing devices that heal in record time November 7th, 2016

Stretchy supercapacitors power wearable electronics August 25th, 2016

Weird, water-oozing material could help quench thirst: Nanorods' behavior first theorized 20 years ago, but not seen until now June 13th, 2016

Nanobiotechnology

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

New active filaments mimic biology to transport nano-cargo: A new design for a fully biocompatible motility engine transports colloidal particles faster than diffusion with active filaments January 11th, 2017

Keystone Nano Announces FDA Approval Of Investigational New Drug Application For Ceramide NanoLiposome For The Improved Treatment Of Cancer January 10th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Research partnerships

Chemistry on the edge: Experiments at Berkeley Lab confirm that structural defects at the periphery are key in catalyst function January 13th, 2017

Recreating conditions inside stars with compact lasers: Scientists offer a new path to creating the extreme conditions found in stars, using ultra-short laser pulses irradiating nanowires January 12th, 2017

Zeroing in on the true nature of fluids within nanocapillaries: While exploring the behavior of fluids at the nanoscale, a group of researchers at the French National Center for Scientific Research discovered a peculiar state of fluid mixtures contained in microscopic channels January 11th, 2017

New active filaments mimic biology to transport nano-cargo: A new design for a fully biocompatible motility engine transports colloidal particles faster than diffusion with active filaments January 11th, 2017

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project