Featured Research

from universities, journals, and other organizations

Radically simple technique developed to grow conducting polymer thin films

Date:
November 2, 2010
Source:
University of California - Los Angeles
Summary:
Oil and water don't mix, but add in some nanofibers and all bets are off. A team of chemists and engineers has developed a new method for coating large surfaces with nanofiber thin films that are both transparent and electrically conductive. Their method involves the vigorous agitation of water, dense oil, and polymer nanofibers. After this solution is sufficiently agitated it spreads over virtually any surface, creating a thin film.

This sequence of images illustrates the growth of the conducting polymer film over 35 seconds. The tube labeled D is immediately after agitation, and the last in the sequence, I, is 35 seconds after agitation. (D) 0 s; (E) 0.5 s; (F) 1 s; (G) 10 s; (H) 30 s; (I) 35 s.
Credit: Image courtesy of UCLA

Oil and water don't mix, but add in some nanofibers and all bets are off.

Related Articles


A team of UCLA chemists and engineers has developed a new method for coating large surfaces with nanofiber thin films that are both transparent and electrically conductive. Their method involves the vigorous agitation of water, dense oil and polymer nanofibers. After this solution is sufficiently agitated it spreads over virtually any surface, creating a film.

"The beauty of this method lies in its simplicity and versatility," said California NanoSystems Institute (CNSI) researcher Richard B. Kaner, a professor of chemistry and biochemistry and a professor of materials science and engineering at the UCLA Henry Samueli School of Engineering and Applied Science. "The materials used are inexpensive and recyclable, the process works on virtually any substrate, it produces a uniform thin film which grows in seconds and the entire thing can be done at room temperature."

Conducting polymers combine the flexibility and toughness of plastics with electrical properties. They have been proposed for applications ranging from printed electronic circuits to supercapacitors but have failed to gain widespread use because of difficulties processing them into films.

"Conducting polymers have enormous potential in electronics, and because this technique works with so many substrates, it can be used in a broad spectrum of applications, including organic solar cells, light-emitting diodes, smart glass and sensors," said Yang Yang, a professor of materials science and engineering at the Samueli School of Engineering and Applied Science and faculty director of the Nano Renewable Energy Center at the CNSI.

One of the potential applications is smart, or switchable, glass that can change between states when an electric current is applied -- for example, switching between see-through and opaque states to let light in or block it. The UCLA research group is applying the technique to other nanomaterials in addition to polymer nanofibers in the hopes of expanding the number of available applications.

The team's solution-based technique, published in the peer-reviewed journal Proceedings of the National Academy of Sciences, was discovered serendipitously when a transparent film of polymer spread up the walls of a container while nanofibers in water were being purified with chloroform.

"What drew me in immediately was the eerie phenomenon of what appeared to be self-propelled fluid flow," said Julio M. D'Arcy, lead author on the PNAS paper and a senior graduate student in the Kaner's UCLA lab.

"Now I can tell people that I make films in L.A.," he joked.

When water and oil are mixed, a blend of droplets is formed, creating a water-oil interface that serves as an entry point for trapping polymer nanofibers at liquid-liquid interfaces. As droplets unite, a change in the concentration of blended solids at the water-oil interface leads to a difference in surface tension. Spreading up a glass wall occurs as result of an attempt to reduce the surface-tension difference. Directional fluid flow leads to a continuously conductive thin film comprised of a single monolayer of polymer nanofibers. The uniformity of the film surface is due to the particles being drawn out of the water-oil interface, sandwiched between two fluids of opposing surface tensions.

Development of the technology is occurring in collaboration with Fibron Technologies Inc., with support from the National Science Foundation through a Small Business Technology Transfer grant. Fibron is a small company that has licensed the technology from UCLA. It was founded by Kaner, who serves as chief scientific adviser, and two of his former Ph.D. students -- Christina Baker and Henry Tran, who have gone on to take leadership roles in the company.

Fibron's CEO, Christian Behrenbruch, said "working with UCLA to develop this technology has been a win-win. It enables us to access incredibly innovative people, but also, the NSF has helped enable the establishment of a formal and transparent IP releationship with the university. The good news is that this technology is moving rapidly into commercial development."

Other techniques exist for creating thin films of conducting polymers, but each technique tends to work only a limited number of applications, or they are not feasible for scaling up. A method has long been sought which would overcome the limitations of each of the previous methods. The water and oil technique, with a bit of nanotechnology thrown in, might provide just that -- a scalable universal method for creating large thin films of conducting polymers.


Story Source:

The above story is based on materials provided by University of California - Los Angeles. The original article was written by Mike Rodewald. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. M. D'Arcy, H. D. Tran, V. C. Tung, A. K. Tucker-Schwartz, R. P. Wong, Y. Yang, R. B. Kaner. Versatile solution for growing thin films of conducting polymers. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1008595107

Cite This Page:

University of California - Los Angeles. "Radically simple technique developed to grow conducting polymer thin films." ScienceDaily. ScienceDaily, 2 November 2010. <www.sciencedaily.com/releases/2010/11/101102091108.htm>.
University of California - Los Angeles. (2010, November 2). Radically simple technique developed to grow conducting polymer thin films. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2010/11/101102091108.htm
University of California - Los Angeles. "Radically simple technique developed to grow conducting polymer thin films." ScienceDaily. www.sciencedaily.com/releases/2010/11/101102091108.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did the Simpsons Figure out the Higgs Boson Particle Years Before Scientists

Did the Simpsons Figure out the Higgs Boson Particle Years Before Scientists

Buzz60 (Mar. 4, 2015) During a 1998 Simpsons episode, Homer Simpson scribbled a seemingly gibberish equation on a chalkboard. Turns out that equation is a shake off from predicting the actual nano mass of the God Particle. Patrick Jones (@Patrick_E_Jones) explains. Video provided by Buzz60
Powered by NewsLook.com
Wearables Now the Must-Haveables

Wearables Now the Must-Haveables

Reuters - Business Video Online (Mar. 3, 2015) Telecom company executives are meeting in Barcelona for the Mobile World Congress, the largest annual trade show for the wireless industry. As Ivor Bennett reports from the show wearable technology is one of the big themes. Video provided by Reuters
Powered by NewsLook.com
Forensic Holodeck Creates 3D Crime Scenes

Forensic Holodeck Creates 3D Crime Scenes

Reuters - Innovations Video Online (Mar. 3, 2015) A holodeck is no longer the preserve of TV sci-fi classic Star Trek, thanks to researchers from the Institute of Forensic Medicine Zurich, who have created what they say is the first system in the world to visualise the 3D data of forensic scans. Jim Drury saw it in operation. Video provided by Reuters
Powered by NewsLook.com
Solar Plane Passes New Test Ahead of World Tour

Solar Plane Passes New Test Ahead of World Tour

AFP (Mar. 2, 2015) A solar-powered plane made a third successful test flight in the United Arab Emirates on Monday ahead of a planned round-the-world tour to promote alternative energy. Duration: 01:05 Video provided by AFP
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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