Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Beyond Elastic: Organic crystal demonstrates superelasticity

07.05.2014

Not only rubber is elastic: There is also another, completely different form of elasticity known as superelasticity. This phenomenon results from a change in crystal structure and was previously only found in alloys and certain inorganic materials. A Japanese scientist has now introduced the first superelastic organic compound in the journal Angewandte Chemie.

Superelasticity, also called “pseudoelasticity”, is the ability of special materials that have undergone extensive deformation to return to their original shape when the pressure is released.

This allows some alloys to be stretched out about ten times more than common spring steel without being permanently deformed. The mechanism is different from that involved in the normal elasticity of rubbery substances. In rubber, the polymer chains are stretched out through strain—no compression is possible.

In superelastic materials, mechanical stress triggers a change in the crystal structure—without the individual atoms changing places. When the stress is removed, the materials return to their former structure. Such substances are interesting candidates for use as building materials with “shape memory” in applications such as “self-repairing” vehicle parts.

Superelastic materials other than metal alloys and ceramics have not appeared for over 80 years since the first report of superelasticity in metal alloys. This phenomenon was previously unknown in organic materials. Satoshi Takamizawa of Yokohama City University has now found superelasticity in an organic crystal for the first time: terepthalamide crystals exhibit superelastic behavior with surprisingly little application of force.

Shear stress on a specific surface of the crystal initially causes the crystal to bend, and then transition to a different crystal phase. The more pressure that is applied, the more this spreads throughout the crystal.

When the tension is released, the phase transition moves back across the crystal, which returns to its original structure. Takamizawa and one of his students were able to repeat this superelastic deformation 100 times without any signs of material fatigue.

The crystal consists of individual sheets of slanted terepthalamide molecules (AAAAA sheet arrangement). Shear stress causes the angles of the molecules within the layers to change, which results in a more densely packed A’BA’BA’B sheet arrangement. The layers are held together by a network of hydrogen bridge bonds, which break under pressure and rearrange during the phase transition.

Possible applications of organic superelastic materials include joints made of a single component and elements for dampening vibrations. In medicine, implants made from these types of materials could be deformed for easy introduction and then return to the desired shape and size when they reach the desired location.

About the Author

Dr. Satoshi Takamizawa is Professor of Inorganic Chemistry at Yokohama City University. His main interest is crystal function in coordination compounds and related organic and inorganic materials.

Author: Satoshi Takamizawa, Yokohama City University (Japan), http://nanochem.sci.yokohama-cu.ac.jp/

Title: A Superelastic Crystal of Terephthalamide

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201311014

Dr. Satoshi Takamizawa | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

Further reports about: Organic compounds function implants inorganic materials pressure structure substances transition

More articles from Life Sciences:

nachricht Stress triggers key molecule to halt transcription of cell's genetic code
28.05.2015 | Stowers Institute for Medical Research

nachricht Chemists discover key reaction mechanism behind the highly touted sodium-oxygen battery
28.05.2015 | University of Waterloo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Solid-state photonics goes extreme ultraviolet

Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.

In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to...

Im Focus: Advance in regenerative medicine

The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.

Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

Im Focus: First electrical car ferry in the world in operation in Norway now

  • Siemens delivers electric propulsion system and charging stations with lithium-ion batteries charged from hydro power
  • Ferry only uses 150 kilowatt hours (kWh) per route and reduces cost of fuel by 60 percent
  • Milestone on the road to operating emission-free ferries

The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Siemens will provide the first H-class power plant technology in Mexico

28.05.2015 | Press release

Merging galaxies break radio silence

28.05.2015 | Physics and Astronomy

A New Kind of Wood Chip: Collaboration Could Yield Biodegradable Computer Chips

28.05.2015 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>