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

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

New metamaterial-enhanced MRI technique tested on humans May 26th, 2017

Controlling 3-D behavior of biological cells using laser holographic techniques May 26th, 2017

Unveiling the quantum necklace: Researchers simulate quantum necklace-like structures in superfluids May 26th, 2017

Materials/Metamaterials

New metamaterial-enhanced MRI technique tested on humans May 26th, 2017

Stanford scientists use nanotechnology to boost the performance of key industrial catalyst May 18th, 2017

Self-healing tech charges up performance for silicon-containing battery anodes May 15th, 2017

Discovery of new transparent thin film material could improve electronics and solar cells: Conductivity is highest-ever for thin film oxide semiconductor material May 6th, 2017

Announcements

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

New metamaterial-enhanced MRI technique tested on humans May 26th, 2017

Controlling 3-D behavior of biological cells using laser holographic techniques May 26th, 2017

Unveiling the quantum necklace: Researchers simulate quantum necklace-like structures in superfluids May 26th, 2017

Textiles/Clothing

New ultrafast flexible and transparent memory devices could herald new era of electronics April 1st, 2017

'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

Nanobiotechnology

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

The brighter side of twisted polymers: Conjugated polymers designed with a twist produce tiny, brightly fluorescent particles with broad applications May 16th, 2017

Research partnerships

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 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