Heavier hydrogen on the atomic scale reduce...( Scientists may be one step closer to...)
| HOME >> BIOLOGY >> TECHNOLOGY |
Scientists may be one step closer to understanding the atomic forces that cause friction, thanks to a recently published study by researchers from the University of Pennsylvania, the University of Houston and the U.S. Department of Energy's Argonne National Laboratory.
The research, led by Robert Carpick of the University of Pennsylvania, found a significant difference in friction exhibited by diamond surfaces that had been coated with different isotopes of hydrogen and then rubbed against a small carbon-coated tip.
Scientists lack a comprehensive model of friction on the nanoscale and only generally grasp its atomic-level causes, which range from local chemical reactions to electronic interactions to phononic, or vibrational, resonances.
To investigate the latter, Argonne scientist Anirudha Sumant and his colleagues used single-crystal diamond surfaces coated with layers of either atomic hydrogen or deuterium, a hydrogen atom with an extra neutron. The deuterium-terminated diamonds had lower friction forces because of their lower vibrational frequencies, an observation that Sumant attributed to that isotope's larger mass. They have also observed same trend on a silicon substrate, which is structurally similar to that of diamond.
Previous attempts to make hydrogen-terminated diamond surfaces relied on the use of plasmas, which tended to etch the material.
"When you're looking at such a small isotopic defect, an objectively tiny change in the mass, you have to be absolutely sure that there are no other complicating effects caused by chemical or electronic interferences or by small topographic variations," Sumant said. "The nanoscale roughening of the diamond surface from the ion bombardment during the hydrogen or deuterium termination process, even though it was at very low level, remained one of our principal concerns."
Sumant and his collaborators had looked at a number of other ways to try to avoid etchin
'/>"/>
| Contact: Steve McGregor smcgregor@anl.gov 630-252-5580 DOE/Argonne National Laboratory Source:Eurekalert |
Related biology technology :
1. Preparative Nondenaturing Gel Electrophoresis to Purify NADP-Specific Glutamate Dehydrogenase From Chlorella, Rev B
2. Virent enters agreement with Shell Oil unit to make hydrogen with biomass
3. Virent gets $1.4 million investment for its hydrogen technology
4. UW students compete to make hydrogen cars, other renewable projects
5. Modine Manufacturing makes hydrogen generator with ChevronTexaco
6. Virent receives $2 million boost for hydrogen energy research
7. UW engineers clear bottleneck in hydrogen production
8. Virent shows off its hydrogen-fuel plans
9. Kodak in vivo imaging system: precise coregistration of molecular imaging with anatomical X-ray imaging in animals
10. Imago provides atomic probe to Australian lab
11. Ni-NTA Superflow Columns - automated large-scale purification of 6xHis-tagged proteins
| Copyright © 2003-2009 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |