Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Repeated Self-Healing Now Possible in Composite Materials

16.04.2014

Researchers at the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign have created a 3D vascular system that allows for high-performance composite materials such as fiberglass to heal autonomously, and repeatedly.

Internal damage in fiber-reinforced composites, materials used in structures of modern airplanes and automobiles, is difficult to detect and nearly impossible to repair by conventional methods. A small, internal crack can quickly develop into irreversible damage from delamination, a process in which the layers separate. This remains one of the most significant factors limiting more widespread use of composite materials.


3D microvascular networks for self-healing composites: Researchers were able to achieve more effective self-healing with the herringbone vascular network (top) over a parallel design (bottom), evidenced by the increased mixing (orange-yellow) of individual healing agents (red and green) across a fracture surface.

However, fiber-composite materials can now heal autonomously through a new self-healing system, developed by researchers in the Beckman Institute’s Autonomous Materials Systems (AMS) Group at the University of Illinois at Urbana-Champaign, led by professors Nancy Sottos, Scott White, and Jeff Moore. 

Sottos, White, Moore, and their team created 3D vascular networks—patterns of microchannels filled with healing chemistries—that thread through a fiber-reinforced composite. When damage occurs, the networks within the material break apart and allow the healing chemistries to mix and polymerize, autonomously healing the material, over multiple cycles. These results were detailed in a paper titled “Continuous self-healing life cycle in vascularized structural composites,” published in Advanced Materials.

“This is the first demonstration of repeated healing in a fiber-reinforced composite system,” said Scott White, aerospace engineering professor and co-corresponding author. “Self-healing has been done before in polymers with different techniques and networks, but they couldn’t be translated to fiber-reinforced composites. The missing link was the development of the vascularization technique.”

“The beauty of this self-healing approach is, we don't have to probe the structure and say, this is where the damage occurred and then repair it ourselves,” said Jason Patrick, a Ph.D. candidate in civil engineering and lead author.  

The vasculature within the system integrates dual networks that are isolated from one other. Two liquid healing agents (an epoxy resin and hardener) are sequestered in two different microchannel networks. 

“When a fracture occurs, this ruptures the separate networks of healing agents, automatically releasing them into the crack plane—akin to a bleeding cut,” Patrick said. “As they come into contact with one another in situ, or within the material, they polymerize to essentially form a structural glue in the damage zone. We tested this over multiple cycles and all cracks healed successfully at nearly 100 percent efficiency.”

Notably, the vascular networks within the structure are not straight lines. In order for the healing agents to combine effectively after being released within the crack, the vessels were overlapped to further promote mixing of the liquids, which both have a consistency similar to maple syrup.

Fiberglass and other composite materials are widely used in aerospace, automotive, naval, civil, and even sporting goods because of their high strength-to-weight ratio—they pack a lot of structural strength into a very lean package. However, because the woven laminates are stacked in layers, it is easier for the structure to separate between the layers, making this self-healing system a promising solution to a long-standing problem and greatly extending their lifetime and reliability.

“Additionally, creating the vasculature integrates seamlessly with typical manufacturing processes of polymer composites, making it a strong candidate for commercial use,” said Nancy Sottos, materials science and engineering professor and co-corresponding author. 

Fiber-composite laminates are constructed by weaving and stacking multiple layers of reinforcing fabric, which are then co-infused with a binding polymer resin. Using that same process, the researchers stitched in a sort of fishing line, made from a bio-friendly polymer and coined “sacrificial fiber,” within the composite. Once the composite was fabricated, the entire system was heated to melt and evaporate the sacrificial fibers, leaving behind hollow microchannels, which became the vasculature for the self-healing system.

This work was supported by the Air Force Office of Scientific Research, the Department of Homeland Security Center of Excellence for Explosives Detection, Mitigation, and Response, and the Army Research Laboratory. Jeff Moore, Kevin Hart, Brett Krull, and Charles Diesendruck were also co-authors on the paper.

August Cassens | Eurek Alert!
Further information:
http://beckman.illinois.edu/news/2014/04/self-healing-composites

More articles from Materials Sciences:

nachricht 3-D printing produces cartilage from strands of bioink
27.06.2016 | Penn State

nachricht Nanoscientists develop the 'ultimate discovery tool'
24.06.2016 | Northwestern University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical lenses, hardly larger than a human hair

3D printing enables the smalles complex micro-objectives

3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines...

Im Focus: Flexible OLED applications arrive

R2D2, a joint project to analyze and development high-TRL processes and technologies for manufacture of flexible organic light-emitting diodes (OLEDs) funded by the German Federal Ministry of Education and Research (BMBF) has been successfully completed.

In contrast to point light sources like LEDs made of inorganic semiconductor crystals, organic light-emitting diodes (OLEDs) are light-emitting surfaces. Their...

Im Focus: Unexpected flexibility found in odorant molecules

High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!

In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...

Im Focus: 3-D printing produces cartilage from strands of bioink

Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."

Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...

Im Focus: First experimental quantum simulation of particle physics phenomena

Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Conference ‘GEO BON’ Wants to Close Knowledge Gaps in Global Biodiversity

28.06.2016 | Event News

ERES 2016: The largest conference in the European real estate industry

09.06.2016 | Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

 
Latest News

Building a better battery

29.06.2016 | Life Sciences

New way out: Researchers show how stem cells exit bloodstream

29.06.2016 | Life Sciences

Crucial peatlands carbon-sink vulnerable to rising sea levels

29.06.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>