Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers produce insulation with lowest thermal conductivity ever

18.12.2006
Material prepared at University of Oregon leads to discovery

A new insulation material with the lowest thermal conductivity ever measured for a fully dense solid has been created at the University of Oregon and tested by researchers at three other U.S. institutions. While far from having immediate application, the principles involved, once understood, could lead to improved insulation for a wide variety of uses, the scientists say.

In a paper published online Dec. 14 on Science Express, in advance of regular publication in the journal Science, the scientists describe how they used a novel approach to synthesize various thicknesses of tungsten diselenide. This effort resulted in a random stacking of tungsten-diselenide planes (WSe2), possibly leading to a localization of lattice vibrations.

The resulting synthesized material, they report, resulted in thermal conductivity -- the rate at which heat flows through a material -- 30 times smaller than that for single-crystal WSe2 and a factor six smaller that the minimum level predicted by theoretical computations for the cross-plane thin films used in the experiments.

Surprisingly, creating a fully disordered structure by bombarding the films with ions to destroy the order in the two-dimensional planes actually increases thermal conductivity, said David C. Johnson, a professor of chemistry at the University of Oregon and member of the UO Materials Science Institute.

"The reason for the extraordinarily low thermal conductivity that we've now achieved is an unusual structure which is crystalline in two directions but has a subtle rotational disorder in the direction of low-heat conduction," Johnson said.

The material prepared in Johnson’s lab "is the closest thing that anyone has found to making a dense solid into a perfect thermal insulator," said co-author and corresponding investigator David G. Cahill, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign. "This material would not be practical for insulating a refrigerator, the wall of a house or parts inside a turbine engine, but the new physical properties displayed by this material might some day point the way toward methods of creating more effective practical insulations."

The approach is a new alternative to one described by Cahill and others in separate journals in the last two years in which researchers reduced minimum thermal conductivity by manipulating thin films of metals and oxides by adjusting interfaces of the materials by only a few nanometers.

"Thermal conductivity is an important property in both conserving energy and in converting between forms of energy," Johnson said. "Obtaining low thermal conductivity in a thermoelectric material, which converts temperature gradients into electrical energy, increases efficiency."

The properties of Johnson's material were measured in Cahill's Illinois laboratory. The structure was analyzed at the Argonne National Laboratory in Argonne, Ill. Computational simulations and molecular modeling of the layered crystals was carried out by researchers at Rensselaer Polytechnic Institute (RPI) in Troy, N.Y.

Jim Barlow | EurekAlert!
Further information:
http://www.uoregon.edu

More articles from Materials Sciences:

nachricht New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University

nachricht Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>