Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
by Staff Writers
Trieste, Italy (SPX) Mar 25, 2014
The experimental and numerical study of the behaviour of polymers in concentrated solutions is a line of research that is still highly active. In the past, it enabled us to understand why materials like rubber have certain elastic properties.
A distinctive feature of these systems is that the long "chained" molecules composing them tend to penetrate each other and interweave at their ends forming very durable bonds that make them always return to their initial conformation whenever they are "stretched".
The behaviour of dense solutions of "ring" polymers, i.e., polymers that form closed loops like rings and have no free ends, is very different. Angelo Rosa, a theoretical physicist from the International School for Advanced Studies (SISSA) in Trieste, and Ralf Everaers from the Ecole Normale Superieure de Lyon devised a highly efficient numerical method to study these materials, a method which they intend to apply to biology in the future.
"Ring polymers - by construction - don't have free ends and so when in a solution they cannot interweave with each other and form bonds as the more common linear polymers do", explains Rosa.
"This causes them to behave very differently from linear polymers. So we wanted to understand the physics of these peculiar solutions and we constructed some models of ring polymers that allowed us to predict their behaviour. We then compared the models we created with other earlier simulations conducted with different methods, and found that they confirmed our findings".
"The really interesting thing about our study is that it considerably reduces analysis time, which means the method is highly efficient", the researcher adds.
"We found that compared to dense solutions of linear polymers, which form the base of the more common visco-elastic materials such as rubber, these materials are much more fragile because a ring polymer interweaves very little with the others and remains "topologically" always confined within a restricted region".
Rosa and Everaers point out that they will now continue to develop their research in the field of biology. "We think that our models of ring polymers are useful to understand chromosomes dissolved in the cell nucleus", says Rosa.
"Even though it isn't a circular polymer, a chromosome behaves in a very similar manner, in that it remains topologically isolated from the other chromosomes dissolved in the cytoplasm for a long time".
International School of Advanced Studies (SISSA)
Space Technology News - Applications and Research
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|