Fitter frames: Nanotubes boost structural integrity of composites
March 26, 2009
Researchers at Rensselaer Polytechnic Institute have discovered a new technique for provoking unusual crazing behavior in epoxy composites. The crazing, which causes the composite to deform into a network of nanoscale pillar-like fibers that bridge together both sides of a crack and slow its growth, could lead to tougher, more durable components for aircraft and automobiles. Credit: Rensselaer/Koratkar
A new research discovery at Rensselaer Polytechnic Institute could lead to tougher, more durable composite frames for aircraft, watercraft, and automobiles.
Epoxy composites are increasingly being incorporated into the design of new jets, planes, and other vehicles. Composite material frames are extremely lightweight, which lowers the overall weight of the vehicle and boosts fuel efficiency. The downside is that epoxy composites can be brittle, which is detrimental to its structural integrity.
Professor Nikhil Koratkar, of Rensselaer's Department of Mechanical, Aerospace, and Nuclear Engineering, has demonstrated that incorporating chemically treated carbon nanotubes into an epoxy composite can significantly improve the overall toughness, fatigue resistance, and durability of a composite frame.
When subjected to repetitive stress, a composite frame infused with treated nanotubes exhibited a five-fold reduction in crack growth rate as compared to a frame infused with untreated nanotubes, and a 20-fold reduction when compared to a composite frame made without nanotubes.
This newfound toughness and crack resistance is due to the treated nanotubes, which enhance the molecular mobility of the epoxy at the interface where the two materials touch. When stressed, this enhanced mobility enables the epoxy to craze - or result in the formation of a network of pillar-like fibers that bridge together both sides of the crack and slow its growth.
"This crazing behavior, and the bridging fibers it produces, dramatically slows the growth rate of a crack," Koratkar said. "In order for the crack to grow, those fibers have to first stretch, deform plastically, and then break. It takes a lot of energy to stretch and break those fibers, energy that would have otherwise gone toward enlarging the crack."
Results of the study were published this week in the journal Small.
Epoxy composites infused with carbon nanotubes are known to be more resistant to cracks than pure epoxy composites, as the nanotubes stitch, or bridge, the two sides of the crack together. Infusing an epoxy with carbon nanotubes that have been functionalized, or treated, with the chemical group amidoamine, however, results in a completely different bridging phenomenon.
At the interface of the functionalized nanotubes and the epoxy, the epoxy starts to craze, which is a highly unusual behavior for this particular type of composite, Koratkar said. The epoxy deforms, becomes more fluid, and creates connective fibers up to 10 microns in length and with a diameter between 100 nanometers and 1,000 nanometers.
"We didn't expect this at all. Crazing is common in certain types of thermoplastic polymers, but very unusual in the type of epoxy composite we used," Koratkar said. "In addition to improved fatigue resistance and toughness, the treated nanotubes also enhanced the stiffness, hardness, and strength of the epoxy composite, which is very important for structural applications."
Koratkar said the aircraft, boat, and automobile industries are increasingly looking to composites as a building material to make vehicle frames and components lighter. His research group plans to further investigate crazing behavior in epoxy composites, in order to better understand why the chemical treatment of nanotubes initiates crazing.
Source: Rensselaer Polytechnic Institute
-
Using nanotubes to detect and repair cracks in aircraft wings, other structures
Sep 27, 2007 |
not rated yet |
0
-
Nanotube Sandwiches Could Lead To Better Composite Materials
May 08, 2006 |
not rated yet |
0
-
'Nanostitching' could strengthen airplane skins, more
Mar 04, 2009 |
not rated yet |
0
-
Catalyst-free chemistry makes self-healing materials more practical
Nov 27, 2007 |
not rated yet |
0
-
A Telescope Made of Moondust
Jul 10, 2008 |
not rated yet |
0
-
Fast photon control brings quantum photonic technologies closer
1 minute ago |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (5) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
polymer nanocomposites
Feb 10, 2012
-
Corrosion Tests on Magnesium
Feb 09, 2012
-
polyethylene copper nanocomposite
Feb 09, 2012
-
Output of xrd analysis
Feb 08, 2012
-
Transport phenomena problem based on problems 18.B11 and 19B.6 from Bird, stewart, lw
Feb 06, 2012
-
Help with material selection - Car Piston
Feb 05, 2012
- More from Physics Forums - Materials & Chemical Engineering
More news stories
'Smart' microcapsules in a single step
(PhysOrg.com) -- A new, single-step method of fabricating microcapsules, which have potential commercial applications in industries including medicine, agriculture and diagnostics, has been developed by researchers ...
Nanotechnology / Nanomaterials
1 hour ago |
5 / 5 (2) |
0
|
Nanostructured electrodes for rechargeable sodium-Ion batteries
Highly efficient 3V cathodes for rechargeable sodium-ion batteries have been developed by users from Argonne National Laboratory's Materials Science, Chemical Sciences & Engineering, and X-ray Sciences Divisions, ...
Nanotechnology / Nanomaterials
51 minutes ago |
5 / 5 (1) |
0
NDSU nano research could impact flexible electronic devices
A discovery by a research team at NDSU and the National Institute of Standards and Technology shows the flexibility and durability of carbon nanotube films and coatings are intimately linked to their electronic properties. ...
Nanotechnology / Nanomaterials
2 hours ago |
5 / 5 (1) |
0
Lab study raises questions over nano-particle impact
Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.
Nanotechnology / Bio & Medicine
19 hours ago |
5 / 5 (10) |
5
New kind of solar cell could capture significantly more energy than current cells
New solar cells could increase the maximum efficiency of solar panels by over 25%, according to scientists from the University of Cambridge.
Feb 08, 2012 |
4.3 / 5 (14) |
14
|
Fast photon control brings quantum photonic technologies closer
(PhysOrg.com) -- Using photons instead of electrons to transmit information could lead to faster and more secure ways to communicate, among other advantages. Now a team of physicists has taken another step toward realizing ...
Transforming galaxies
(PhysOrg.com) -- Many of the Universe's galaxies are like our own, displaying beautiful spiral arms wrapping around a bright nucleus. Examples in this stunning image, taken with the Wide Field Camera 3 on ...
New ability to regrow blood vessels holds promise for treatment of heart disease
(Medical Xpress) -- University of Texas at Austin researchers have demonstrated a new and more effective method for regrowing blood vessels in the heart and limbs a research advancement that could have ...
A continent ablaze in auroral and manmade light
The North American continent is literally set ablaze in a confluence of Auroral and Manmade light captured in spectacular new videos snapped by the astronauts serving aboard the International Space Station ...
New tumor suppressor gene identified
A recent study published in Clinical Cancer Research suggests that the protein hVps37A suppresses tumor growth in ovarian cancer. The work, which was funded by the Austrian Science Fund FWF, shows, for th ...
A lost world? How zooarchaeology can inform biodiversity conservation
A new study of tropical forests will provide a 50,000-year perspective on how animal biodiversity has changed, explored through an archaeological investigation of animal bones.
Mar 26, 2009
Rank: not rated yet