Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pulling Polymers Leads to New Insights into their Mechanical Behavior

04.03.2014

In collaboration with colleagues from Berlin and Madrid, researchers at the Department of Physics at the University of Basel have pulled up isolated molecular chains from a gold surface, using the tip of an atomic force microscope (AFM). The observed signal provides insight into the detachment force and binding energy of molecules. The results have been published in the renowned scientific journal PNAS.

Atomic force microscopy is a method normally used for imaging matter with very high resolution. The sharp tip of the microscope is used to scan the surface line by line. The resolution is so high, that single atoms can be seen.


The tip of an AFM pulling off a molecular chain vertically from a gold surface.

(Illustration: Shigeki Kawai)

“This method is roughly equivalent to using the tip of the Matterhorn to scan the surface of a tennis ball”, says Prof. Ernst Meyer of the Department for Physics at the University of Basel. Due to an improved method, the scientists are now able to investigate the mechanical behavior of a single polymer being pulled off a surface.

Using the tip of the AFM, the researchers were able to pull single chains of molecules (polymers) off a gold surface. “The molecule-surface interaction during pulling is so weak that each chain link (molecular unit) detaches successively.

Thus, the whole chain can be pulled off almost vertically to the surface”, explains Meyer. By analyzing the observed oscillations, the researchers are able to make quantitative statements on the binding energy of each molecular unit.

Motion without friction

Furthermore, the experiments showed that the polymers could be pulled off with almost no lateral forces. This remarkable behavior of nearly frictionless motion was predicted by a theoretical model and has now been verified for molecules on a gold surface.

Previously, the mechanical behavior of single polymer during pulling from a surface had never been investigated with atomic-scale resolution. The findings and calculations of the research team now provide detailed insight into this process for the first time.

Such investigations are not only of interest for the field of physics, but also for biology and chemistry, since the method of pulling polymers from surfaces can also be applied to biological molecules. So far, valuable insights have been obtianed into the folding and unfolding of DNA and proteins. Chemical reactions of small biopolymer sub units or complex polymer chains under the influence of traction forces and catalytic nanoparticles could be investigated with this new method.

Original source
Shigeki Kawai, Matthias Koch, Enrico Gnecco, Ali Sadeghi, Rémy Pawlak, Thilo Glatzel, Jutta Schwarz, Stefan Goedecker, Stefan Hecht, Alexis Baratoff, Leonhard Grill and Ernst Meyer
Quantifying the atomic-level mechanics of single long physisorbed molecular chains
PNAS Early Edition | doi: 10.1073/pnas.1319938111

Further information
Prof. Ernst Meyer, University of Basel, Department of Physics, phone: +41 61 267 37 24, email: ernst.meyer@unibas.ch

Weitere Informationen:

http://unibas.ch/index.cfm?uuid=872F3068BB9FFB71DC9D3BF5D34565BC&type=search...

Olivia Poisson | Universität Basel

More articles from Physics and Astronomy:

nachricht A blueprint for clearing the skies of space debris
17.04.2015 | RIKEN

nachricht Quantum Physics – Hot and Cold at the Same Time
17.04.2015 | Ruprecht-Karls-Universität Heidelberg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Astronomers reveal supermassive black hole's intense magnetic field

Astronomers from Chalmers University of Technology have used the giant telescope Alma to reveal an extremely powerful magnetic field very close to a supermassive black hole in a distant galaxy

Astronomers from Chalmers University of Technology have used the giant telescope Alma to reveal an extremely powerful magnetic field very close to a...

Im Focus: A “pin ball machine” for atoms and photons

A team of physicists from MPQ, Caltech, and ICFO proposes the combination of nano-photonics with ultracold atoms for simulating quantum many-body systems and creating new states of matter.

Ultracold atoms in the so-called optical lattices, that are generated by crosswise superposition of laser beams, have been proven to be one of the most...

Im Focus: UV light robot to clean hospital rooms could help stop spread of 'superbugs'

Can a robot clean a hospital room just as well as a person?

According to new research out of the Texas A&M Health Science Center College of Medicine, that is indeed the case. Chetan Jinadatha, M.D., M.P.H., assistant...

Im Focus: Graphene pushes the speed limit of light-to-electricity conversion

Researchers from ICFO, MIT and UC Riverside have been able to develop a graphene-based photodetector capable of converting absorbed light into an electrical voltage at ultrafast timescales

The efficient conversion of light into electricity plays a crucial role in many technologies, ranging from cameras to solar cells.

Im Focus: Study shows novel pattern of electrical charge movement through DNA

Electrical charges not only move through wires, they also travel along lengths of DNA, the molecule of life. The property is known as charge transport.

In a new study appearing in the journal Nature Chemistry, authors, Limin Xiang, Julio Palma, Christopher Bruot and others at Arizona State University's...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HHL's Entrepreneurship Conference on FinTech

13.04.2015 | Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

 
Latest News

Engineer Improves Rechargeable Batteries with MoS2 Nano 'Sandwich'

17.04.2015 | Power and Electrical Engineering

Comparing Climate Models to Real World Shows Differences in Precipitation Intensity

17.04.2015 | Earth Sciences

A blueprint for clearing the skies of space debris

17.04.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>