Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Researchers create new 'smart' material with potential biomedical, environmental uses

Brown University researchers have created a hybrid material out of seaweed-derived alginate and the nanomaterial graphene oxide. The 3-D printing technique used to make the material enables the creation of intricate structures, including the one above, which mimics that atomic lattice a graphene.

CREDIT
Wong Lab / Brow University
Brown University researchers have created a hybrid material out of seaweed-derived alginate and the nanomaterial graphene oxide. The 3-D printing technique used to make the material enables the creation of intricate structures, including the one above, which mimics that atomic lattice a graphene. CREDIT Wong Lab / Brow University

Abstract:
Brown University researchers have shown a way to use graphene oxide (GO) to add some backbone to hydrogel materials made from alginate, a natural material derived from seaweed that's currently used in a variety of biomedical applications. In a paper published in the journal Carbon, the researchers describe a 3-D printing method for making intricate and durable alginate-GO structures that are far stiffer and more fracture resistant that alginate alone.

Researchers create new 'smart' material with potential biomedical, environmental uses

Providence, RI | Posted on November 23rd, 2018

"One limiting factor in the use of alginate hydrogels is that they're very fragile -- they tend to fall apart under mechanical load or in low salt solutions," said Thomas Valentin, a Ph.D. student in Brown's School of Engineering who led the work. "What we showed is by including graphene oxide nanosheets, we can make these structures much more robust."

The material is also capable of becoming stiffer or softer in response to different chemical treatments, meaning it could be used to make "smart" materials that are able to react to their surroundings in real time, the research shows. In addition, alginate-GO retains alginate's ability to repel oils, giving the new material potential as a sturdy antifouling coating.

The 3-D printing method used to make the materials is known as stereolithography. The technique uses an ultraviolet laser controlled by a computer-aided design system to trace patterns across the surface of a photoactive polymer solution. The light causes the polymers to link together, forming solid 3-D structures from the solution. The tracing process is repeated until an entire object is built layer-by-layer from the bottom up. In this case the polymer solution was made using sodium alginate mixed with sheets of graphene oxide, a carbon-based material that forms one-atom-thick nanosheets that are stronger pound-for-pound than steel.

One advantage to the technique is that the sodium alginate polymers link through ionic bonds. The bonds are strong enough to hold the material together, but they can be broken by certain chemical treatments. That gives the material the ability to respond dynamically to external stimuli. Previously, the Brown researchers showed that this "ionic crosslinking" can be used to create alginate materials that degrade on demand, rapidly dissolving when treated with a chemical that sweeps away ions from the material's internal structure.

For this new study, the researchers wanted to see how graphene oxide might change mechanical properties of alginate structures. They showed that alginate-GO could be made twice as stiff as alginate alone, and far more resistant to failure through cracking.

"The addition of graphene oxide stabilizes the alginate hydrogel with hydrogen bonding," said Ian Y. Wong, an assistant professor of engineering at Brown and the paper's senior author. "We think the fracture resistance is due to cracks having to detour around the interspersed graphene sheets rather than being able to break right though homogeneous alginate."

The extra stiffness enabled the researchers to print structures that had overhanging parts, which would have been impossible using alginate alone. Moreover, the increased stiffness didn't prevent alginate-GO also from responding to external stimuli like alginate alone can. The researchers showed that by bathing the materials in a chemical that removes its ions, the materials swelled up and became much softer. The materials regained their stiffness when ions were restored through bathing in ionic salts. Experiments showed that the materials' stiffness could be tuned over a factor of 500 by varying their external ionic environment.

That ability to change its stiffness could make alginate-GO useful in a variety of applications, the researchers say, including dynamic cell cultures.

"You could imagine a scenario where you can image living cells in a stiff environment and then immediately change to a softer environment to see how the same cells might respond," Valentin said. That could be useful in studying how cancer cells or immune cells migrate through different organs throughout the body.

And because alginate-GO retains the powerful oil-repellant properties of pure alginate, the new material could make an excellent coating to keep oil and other grime from building up on surfaces. In a series of experiments, the researchers showed that a coating of alginate-GO could keep oil from fouling the surface of glass in highly saline conditions. That could make alginate-GO hydrogels useful for coatings and structures used in marine settings, the researchers say.

"These composite materials could be used as a sensor in the ocean that can keep taking readings during an oil spill, or as an antifouling coating that helps to keep ship hulls clean," Wong said. The extra stiffness afforded by the graphene would make such materials or coatings far more durable than alginate alone.

The researchers plan to continue experimenting with the new material, looking for ways to streamline its production and continue to optimize its properties.

###

Additional co-authors of the study include Alexander K. Landauer, Luke C. Morales, Eric M. DuBois, Shashank Shukla, Muchun Liu, and Lauren H. Stephens of Brown University, as well as Christian Franck of the University of Wisconsin, and Po-Yen Chen of the National University of Singapore. The research was supported by the U.S. Department of Education's GAANN Training Grant in Applications and Implications of Nanotechnology, (P200A150037), the National Science Foundation (DGE-1058262) and a Brown University Hibbitt Postdoctoral Fellowship.

####

For more information, please click here

Contacts:
Kevin Stacey

401-863-3766

Copyright © Brown University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Optimized method to detect high-dimensional entanglement December 3rd, 2021

Scientists edge closer to probe that would inspect atherosclerotic plaques by forcing molecules to sound their presence December 3rd, 2021

Two-dimensional bipolar magnetic semiconductors with high Curie-temperature and electrically controllable spin polarization realized in exfoliated Cr(pyrazine)2 monolayers December 3rd, 2021

Review on the femtosecond laser precision micro/nano-engineering December 3rd, 2021

Graphene/ Graphite

Development of a single-process platform for the manufacture of graphene quantum dots: Precisely controls the bonding configuration of heteroatoms in graphene quantum dots through simple chemical processes. Practical application and commercialization in various fields is expected December 3rd, 2021

Graphene nanotubes offer an efficient replacement for carbon additives in conductive electrical heating paints November 3rd, 2021

Graphene nanotubes provide a shortcut to add conductivity to powder coatings October 1st, 2021

National 2D materials research center wins NSF funding: Boise State joins Penn State, Rice for Phase II expansion of ATOMIC center August 20th, 2021

From anti-icing coatings to protection of containers with flammable liquids: heating films with graphene nanotubes enter the market August 20th, 2021

3D & 4D printing/Additive-manufacturing

Nanoscale lattices flow from 3D printer: Rice University engineers create nanostructures of glass and crystal for electronics, photonics October 15th, 2021

Dynamic 3D printing process features a light-driven twist: Light provides freedom to control each layer and improves precision and speed February 4th, 2021

Russian scientists improve 3D printing technology for aerospace composites using oil waste November 27th, 2020

Hydrogels

Nanocellulose decorated with proteins is suitable for 3D cell culturing September 24th, 2021

Synthetic gelatin-like material mimics lobster underbelly’s stretch and strength: The membrane’s structure could provide a blueprint for robust artificial tissues April 23rd, 2021

Marine/Watercraft

Expanding the freedom of design: powder coating on FRP thanks to conductive gelcoats with graphene nanotubes March 3rd, 2021

A quantum material-based diagnostic paint to sense problems before structural failure October 23rd, 2020

Govt.-Legislation/Regulation/Funding/Policy

Light speed advances: UD Prof. Tingyi Gu receives DARPA Young Faculty Award December 3rd, 2021

Immune system-stimulating nanoparticle could lead to more powerful vaccines: The potent new adjuvant could be used to help make vaccines against HIV and other infectious diseases December 3rd, 2021

How ultracold, superdense atoms become invisible: A new study confirms that as atoms are chilled and squeezed to extremes, their ability to scatter light is suppressed November 19th, 2021

Energizer atoms: JILA researchers find new way to keep atoms excited November 19th, 2021

Possible Futures

Researchers develop polyimide-mica nanocomposite film with high resistance to low earth orbit environments December 3rd, 2021

Researchers realize ultra-high precision search for exotic interactions December 3rd, 2021

Optimized method to detect high-dimensional entanglement December 3rd, 2021

Scientists edge closer to probe that would inspect atherosclerotic plaques by forcing molecules to sound their presence December 3rd, 2021

Sensors

Quantum brain sensors could be crucial in spotting dementia after University of Sussex scientists find they can track brain waves: Sensors introduce important new method to spot bio-marker for brain diseases • Accurate timings of when brain signals fire demonstrated for first tim November 19th, 2021

New microscopy method offers 3D tracking of 100 single molecules at once November 19th, 2021

How to program DNA robots to poke and prod cell membranes: A discovery of how to build little blocks out of DNA and get them to stick to lipids has implications for biosensing and mRNA vaccines October 15th, 2021

Leibniz Prize winner Professor Dr. Oliver G. Schmidt moves to Chemnitz University of Technology: President Professor Dr. Gerd Strohmeier refers to an 'absolute top transfer' September 10th, 2021

Discoveries

Researchers develop polyimide-mica nanocomposite film with high resistance to low earth orbit environments December 3rd, 2021

Researchers realize ultra-high precision search for exotic interactions December 3rd, 2021

Optimized method to detect high-dimensional entanglement December 3rd, 2021

Scientists edge closer to probe that would inspect atherosclerotic plaques by forcing molecules to sound their presence December 3rd, 2021

Announcements

Scientists edge closer to probe that would inspect atherosclerotic plaques by forcing molecules to sound their presence December 3rd, 2021

Two-dimensional bipolar magnetic semiconductors with high Curie-temperature and electrically controllable spin polarization realized in exfoliated Cr(pyrazine)2 monolayers December 3rd, 2021

Review on the femtosecond laser precision micro/nano-engineering December 3rd, 2021

Development of a single-process platform for the manufacture of graphene quantum dots: Precisely controls the bonding configuration of heteroatoms in graphene quantum dots through simple chemical processes. Practical application and commercialization in various fields is expected December 3rd, 2021

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Using green tea as reducing reagent for the preparation of nanomaterials to synthesize ammonia December 3rd, 2021

Researchers develop polyimide-mica nanocomposite film with high resistance to low earth orbit environments December 3rd, 2021

Researchers realize ultra-high precision search for exotic interactions December 3rd, 2021

Development of a single-process platform for the manufacture of graphene quantum dots: Precisely controls the bonding configuration of heteroatoms in graphene quantum dots through simple chemical processes. Practical application and commercialization in various fields is expected December 3rd, 2021

Research partnerships

Scientists develop promising vaccine method against recurrent UTI November 19th, 2021

Quantum brain sensors could be crucial in spotting dementia after University of Sussex scientists find they can track brain waves: Sensors introduce important new method to spot bio-marker for brain diseases • Accurate timings of when brain signals fire demonstrated for first tim November 19th, 2021

Quantum Collaboration: Two UCSB scientists receive award to partner with Cisco’s new Quantum Research Team November 3rd, 2021

A simple way to get complex semiconductors to assemble themselves: Much like crystallizing rock candy from sugar syrup, the new method grows 2D perovskites precisely layered with other 2D materials to produce crystals with a wide range of electronic properties September 17th, 2021

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project