Featured Research

from universities, journals, and other organizations

Supersonic spray delivers high-quality graphene layer

Date:
May 28, 2014
Source:
University of Illinois at Chicago
Summary:
A simple, inexpensive spray method that deposits a graphene film can heal manufacturing defects and produce a high-quality graphene layer on a range of substrates.

Using a supersonic spray, graphene flakes with deformed pentagonal and heptagonal structures stretch on impact and spring into a perfect hexagonal graphene lattice. This opens the way to scale up from the microscopic to large scale applications.
Credit: Suman Sinha-Ray

A simple, inexpensive spray method that deposits a graphene film can heal manufacturing defects and produce a high quality graphene layer on a range of substrates, report researchers at the University of Illinois at Chicago and Korea University.

Their study is available online in the journal Advanced Functional Materials.

Graphene, a two-dimensional wonder-material composed of a single layer of carbon atoms, is strong, transparent, and an excellent conductor of electricity. It has potential in a wide range of applications, such as reinforcing and lending electrical properties to plastics; creating denser and faster integrated circuits; and building better touch screens.

Although the potential uses for graphene seem limitless, there has been no easy way to scale up from microscopic to large-scale applications without introducing defects, says Alexander Yarin, UIC professor of mechanical and industrial engineering and co-principal investigator on the study.

"Normally, graphene is produced in small flakes, and even these small flakes have defects," Yarin said. Worse, when you try to deposit them onto a large-scale area, defects increase, and graphene's useful properties -- its "magic" -- are lost, he said.

Yarin first turned to solving how to deposit graphene flakes to form a consistent layer without any clumps or spaces. He went to Sam S. Yoon, professor of mechanical engineering at Korea University and co-principal investigator on the study.

Yoon had been working with a unique kinetic spray deposition system that exploits the supersonic acceleration of droplets through a Laval nozzle. Although Yoon was working with different materials, Yarin believed his method might be used to deposit graphene flakes into a smooth layer.

Their supersonic spray system produces very small droplets of graphene suspension, which disperse evenly, evaporate rapidly, and reduce the tendency of the graphene flakes to aggregate.

But to the researchers' surprise, defects inherent in the flakes themselves disappeared, as a by-product of the spray method. The result was a higher quality graphene layer, as found in the analysis by another collaborator, Suman Sinha-Ray, senior researcher at United States Gypsum and UIC adjunct professor of mechanical and industrial engineering.

The researchers demonstrated that the energy of the impact stretches the graphene and restructures the arrangement of its carbon atoms into the perfect hexagons of flawless graphene.

"Imagine something like Silly Putty hitting a wall -- it stretches out and spreads smoothly," said Yarin. "That's what we believe happens with these graphene flakes. They hit with enormous kinetic energy, and stretch in all directions.

"We're tapping into graphene's plasticity -- it's actually restructuring."

Other attempts to produce graphene without defects or to remove flaws after manufacture have proved difficult and prohibitively expensive, Yarin said.

The new method of deposition, which allows graphene to "heal" its defects during application, is simple, inexpensive, and can be performed on any substrate with no need for post-treatment, he said.

Yarin and his Korean colleagues hope to continue their successful collaboration and foster the development of industrial-scale applications of graphene.

Jung-Jae Park, Jung-Gun Lee and You-Hong Cha of Korea University; Sang-Hoon Bae and Jong-Hyun Ahn of Yonsei University; and Yong Chae Jung and Soo Min Kim of the Korea Institute of Science and Technology are co-authors on the paper.

Initial support for the collaboration between Yarin's group at UIC and Yoon's group at Korean University was provided by the Office of International Affairs Nuveen International Development Fund at UIC and by Korea University.


Story Source:

The above story is based on materials provided by University of Illinois at Chicago. The original article was written by Jeanne Galatzer-Levy. Note: Materials may be edited for content and length.


Journal Reference:

  1. Do-Yeon Kim, Suman Sinha-Ray, Jung-Jae Park, Jong-Gun Lee, You-Hong Cha, Sang-Hoon Bae, Jong-Hyun Ahn, Yong Chae Jung, Soo Min Kim, Alexander L. Yarin, Sam S. Yoon. Self-Healing Reduced Graphene Oxide Films by Supersonic Kinetic Spraying. Advanced Functional Materials, 2014; DOI: 10.1002/adfm.201400732

Cite This Page:

University of Illinois at Chicago. "Supersonic spray delivers high-quality graphene layer." ScienceDaily. ScienceDaily, 28 May 2014. <www.sciencedaily.com/releases/2014/05/140528114118.htm>.
University of Illinois at Chicago. (2014, May 28). Supersonic spray delivers high-quality graphene layer. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2014/05/140528114118.htm
University of Illinois at Chicago. "Supersonic spray delivers high-quality graphene layer." ScienceDaily. www.sciencedaily.com/releases/2014/05/140528114118.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins