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 Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>