Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ORNL thermomagnetic processing method provides path to new materials

07.11.2014

For much the same reason LCD televisions offer eye-popping performance, a thermomagnetic processing method developed at the Department of Energy’s Oak Ridge National Laboratory can advance the performance of polymers.

Polymers are used in cars, planes and hundreds of consumer products, and scientists have long been challenged to create polymers that are immune to shape-altering thermal expansion. One way to achieve this goal is to develop highly directional crystalline structures that mimic those of transparent liquid crystal diode, or LCD, films of television and computer screens.


The high magnetic field environments are provided by fully recondensing commercial prototype superconducting magnet processing system. The electromagnetic fields turn and align the liquid crystal phase forming a pseudo super-structure of ordered domains. This leads to advanced physical properties such as near-zero coefficient of thermal expansion.

Unfortunately, polymers typically feature random microstructures rather than the perfectly aligned microstructure – and transparency – of the LCD film.

ORNL’s Orlando Rios and collaborators at Washington State University have pushed this barrier aside with a processing system that changes the microstructure and mechanical properties of a liquid crystalline epoxy resin.

Their finding, outlined in a paper published in the American Chemical Society journal Applied Materials and Interfaces, offers a potential path to new structural designs and functional composites with improved properties.

The method combines conventional heat processing with the application of powerful magnetic fields generated by superconducting magnets. This provides a lever researchers can use to control the orientation of the molecules and, ultimately, the crystal alignment.

“In this way, we can achieve our goal of a zero thermal expansion coefficient and a polymer that is highly crystalline,” said Rios, a member of ORNL’s Deposition Science Group. “And this means we have the potential to dial in the desired properties for the epoxy resin polymers that are so prevalent today.”

Epoxy is commonly used in structural composites, bonded magnets and coatings. Rios noted that thermosets such as epoxy undergo a chemical cross-linking reaction that hardens or sets the material. Conventional epoxy typically consists of randomly oriented molecules with the molecular chains pointing in every direction, almost like a spider web of atoms.

“Using thermomagnetic processing and magnetically responsive molecular chains, we are able to form highly aligned structures analogous to many stacks of plates sitting on a shelf,” Rios said. “We confirmed the directionality of this structure using X-ray measurements, mechanical properties and thermal expansion.”

Co-authors of the paper, “Thermomagnetic processing of liquid crystalline epoxy resins and their mechanical characterization using nanoindentation,” are Yuzhan Li and Michael Kessler of Washington State’s School of Mechanical and Materials Engineering.

The ORNL portion of the research was supported by the Critical Materials Institute, an Energy Innovation Hub funded by DOE’s Office of Energy Efficiency and Renewable Energy. Washington State’s research was funded by the Air Force Office of Scientific Research.

UT-Battelle manages ORNL for the Department of Energy's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/ 

Ron Walli | EurekAlert!
Further information:
http://www.ornl.gov/ornl/news/news-releases/2014/ornl-thermomagnetic-processing-method-provides-path-to-new-materials

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>