Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Theory Explains Mysterious Nature of Glass

01.10.2008
The history of glass dates back 5,000 years, yet its nature still perplexes scientists. How do glassy materials make the transition from a molten state to a solid? Richard Wool, professor of chemical engineering at the University of Delaware, thinks he has the answer -- Twinkling Fractal Theory.

Archaeological evidence suggests that glass was first made in the Middle East sometime around 3000 B.C. However, almost 5,000 years later, scientists are still perplexed about how glassy materials make the transition from a molten state to a solid. Richard Wool, professor of chemical engineering at UD, thinks he has the answer.

What distinguishes glasses from other materials is that even after hardening, they retain the molecular disorder of a liquid. In contrast, other liquids--for example, water--assume an ordered crystal pattern when they harden. Glass does not undergo such a neat phase transition; rather, the molecules simply slow down gradually until they are stuck in an odd state somewhere between a liquid and a solid.

In a paper to be published later this year in the Journal of Polymer Science Part B: Polymer Physics, Wool documents a new conceptual approach, known as the Twinkling Fractal Theory (TFT), to understanding the nature and structure of the glass transition in amorphous materials. The theory provides a quantitative way of describing a phenomenon that was previously explained from a strictly empirical perspective.

“The TFT enables a number of predictions of universal behavior to be made about glassy materials of all sorts, including polymers, metals and ceramics,” Wool says.

Another difference between glasses and more conventional materials is that their transition from the liquid to the solid state does not occur at a standard temperature, like that of water to ice, but instead is rate-dependent: the more rapid the cooling, the higher the glass transition temperature.

Wool discovered that as a liquid cools toward the glassy state, the atoms form clusters that eventually become stable and percolate near the glass transition temperature. The percolating clusters are stable fractals, or structures with irregular or fragmented shapes.

“At the glass transition temperature, these fractals appear to twinkle in a specific frequency spectrum,” Wool says. “The twinkling frequencies determine the kinetics of the glass transition temperature and the dynamics of the glassy state.”

The theory has been validated by experimental results reported by Nathan Israeloff, a physics professor at Northeastern University. “He was not aware of the TFT,” Wool says, “but his results fit my theory in extraordinarily explicit detail.”

TFT was developed as an outgrowth of Wool's research on bio-based materials such as soy-based composites. “It was my need to solve issues in the development of these materials that led me to the theory,” he says.

For now, Wool is content to view the theory as a portal into materials science and solid-state physics that others can use to go in new directions. “Acceptance will come when people recognize that it works,” he says.

TFT has the potential to contribute to better understanding of such phenomena as fracture, aggregation and physical aging of materials. “It is also giving us new insights into the peculiarities of nanomaterials, which behave very differently from their macroscopic counterparts,” Wool says.

Wool, who earned his doctorate at the University of Utah, joined the UD faculty in 1995. An affiliated faculty member in the Center for Composite Materials, he was recently featured on the Sundance Channel series “Big Ideas for a Small Planet.”

Andrea Boyle | Newswise Science News
Further information:
http://www.udel.edu

Further reports about: Liquid Molecules Polymer Solid TFT Theory Twinkling Fractal Theory Wool glass glassy materials liquids transition

More articles from Life Sciences:

nachricht The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

Quantum optical sensor for the first time tested in space – with a laser system from Berlin

23.01.2017 | Physics and Astronomy

The interactome of infected neural cells reveals new therapeutic targets for Zika

23.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>