Featured Research

from universities, journals, and other organizations

New approach to form non-equilibrium structures

Date:
July 24, 2014
Source:
Northwestern University
Summary:
Researchers get closer to understanding the fundamentals of non-equilibrium, self-assembled structures, unlocking potential in a variety of fields. By injecting energy through oscillations, researchers can force particles to self assemble under non-equilibrium conditions, they report.

Although most natural and synthetic processes prefer to settle into equilibrium -- a state of unchanging balance without potential or energy -- it is within the realm of non-equilibrium conditions where new possibilities lie. Non-equilibrium systems experience constant changes in energy and phases, such as temperature fluctuations, freezing and melting, or movement. These conditions allow humans to regulate their body temperature, airplanes to fly, and Earth to rumble with seismic activity.

But even though these conditions exist naturally and are required for the most basic life, they are rarely understood and difficult to find in synthetic materials.

"In equilibrium thermodynamics, we know everything," said Northwestern's Igal Szleifer. "Non-equilibrium thermodynamics is an old subject, but we don't have a complete set of rules for it. There are no guidelines."

Szleifer is the Christina Enroth-Cugell Professor of Biomedical Engineering and professor of chemical and biological engineering in the McCormick School of Engineering and Applied Science, professor of chemistry in the Weinberg College of Arts and Science, and professor of medicine at the Feinberg School of Medicine.

Szleifer, his postdoctoral fellow Mario Tagliazucchi, and Emily Weiss, the Irving M. Klotz Research Professor of Chemistry at Weinberg, have developed a new technique for creating non-equilibrium systems, which will bring scientists closer to understanding the fundamentals of the mysterious topic. Their work is described in the paper "Dissipative self-assembly of particles interacting through time-oscillatory potentials," which was featured in the June 23 issue of the Proceedings of the National Academy of Sciences.

Past research has shown that theoretical, non-equilibrium particle structures can self-organize when continuously injected with energy, but strategies for injecting energy were limited.

"Think about us as humans," Szleifer said. "For us to be alive, we need to use energy all the time. In order to do that, we have to be out of equilibrium. We are trying to understand non-equilibrium assembly systems, so we have to give them energy."

Using models and simulations, Tagliazucchi, Weiss, and Szleifer found that they could give equilibrium systems energy by using a mixture of pH-responsive particles. Varying pH levels flipped the electric charges of the particles, causing them to oscillate and create the energy needed to assemble into non-equilibrium structures.

"By controlling the structure of the material, we can control its properties as well," Szleifer said. "The moment you stop the oscillations, the structure disappears."

The oscillatory method has allowed Szleifer and his collaborators to create novel structures that are impossible to find in equilibrium conditions. He said scientists could potentially determine how they want particles to interact and then tailor oscillations to lead to that outcome.

"For a number of years, my group has tried to find rules for self assembly," Szleifer said. "This is building toward that. We want to make guidelines for experimentalists."


Story Source:

The above story is based on materials provided by Northwestern University. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Tagliazucchi, E. A. Weiss, I. Szleifer. Dissipative self-assembly of particles interacting through time-oscillatory potentials. Proceedings of the National Academy of Sciences, 2014; 111 (27): 9751 DOI: 10.1073/pnas.1406122111

Cite This Page:

Northwestern University. "New approach to form non-equilibrium structures." ScienceDaily. ScienceDaily, 24 July 2014. <www.sciencedaily.com/releases/2014/07/140724171954.htm>.
Northwestern University. (2014, July 24). New approach to form non-equilibrium structures. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2014/07/140724171954.htm
Northwestern University. "New approach to form non-equilibrium structures." ScienceDaily. www.sciencedaily.com/releases/2014/07/140724171954.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
What Is Magic Leap, And Why Is It Worth $500M?

What Is Magic Leap, And Why Is It Worth $500M?

Newsy (Oct. 22, 2014) — Magic Leap isn't publicizing much more than a description of its product, but it’s been enough for Google and others to invest more than $500M. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins