Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanometer-thick clay may yield groundbreaking technology

16.04.2003


An ultrathin film containing 1-nanometer thick clay particles has been created for the first time, an accomplishment that may yield new materials and devices for medicine, electronics and engineering, according to Purdue University and Belgian scientists.


Cliff Johnston uses a laser to look at a clay particle in his Purdue University lab. The laser helps Johnston study the structure and orientation of the clay. This particular layer is approximately 1 million times the thickness of the one nanometer-thick layer researchers recently developed. (Purdue Agricultural Communications photo/Tom Campbell)


Cliff Johnston peers through a model of a 1 nanometer-thick layer of clay at his Purdue University laboratory. It would take 70,000 of the clay layers to equal the thickness of one human hair. Using these ultrathin films, researchers hope to develop new materials that will benefit medicine, electronics and engineering. Johnston, an environmental chemist in the agronomy department, also is a researcher in Purdue’s Birck Nanotechnology Center. (Agricultural Communications photo/Tom Campbell – model courtesy of Darrell Schulze)



Using a method that captures clay particles on a crystal, Purdue and Katholieke Universiteit Leuven research partners were able to produce, see and manipulate a single layer of clay. It would take 70,000 of these layers to equal the thickness of a human hair. The thickness of one clay particle is about 1 nanometer, and being able to see one of these layers is equivalent to standing on Earth and being able to see footprints on the moon.

The researchers’ joint findings will be reported in the May 27 issue of the journal Langmuir, a publication of the American Chemical Society. The report is currently on the publication’s Web site .


"Once you can control and manipulate nano-sized clay particles, then you have the ability to create smart materials by combining the structural support provided by the clay with the functionality of organic molecules, such as dye, enzymes, proteins and polymers," said Cliff Johnston, Purdue professor of agronomy and an environmental chemist. "That allows us to build the clay and the organic molecules into more complex structures."

This could lead to development of sensors to more quickly detect biological and chemical agents, the creation of stronger plastics and other materials, such as self-sealing substances for use on spacecraft.

"When we use an ultrathin hybrid film to make a device, such as a sensor, it will respond faster than a larger device," said Johnston, who also is a researcher with the Birck Nanotechnology Center in Purdue’s Discovery Park.

Clay minerals already have a variety of uses in products such as nanocomposites, vaccines, catalysts and plastics. In these materials, the clay particles consist of many layers.

Creating a film that has a single layer of clay allows researchers to work with the mineral in new ways. Because clay behaves differently when it’s in bulk form composed of numerous layers, its value multiplies in a single-layer form, Johnston said.

"We’re interested in making clay particles smart materials by combining them with functional organic molecules to form hybrid materials," he said. "By doing this, we open a whole spectrum of materials we can develop so they will respond in a particular way in a particular environment.

"It could be a dye molecule that is one color in the presence of a particular contaminant or is sensitive to a change in pH or to a whole range of different things."

Clay particles can provide a semirigid structure or template for organic molecules, Johnston said. By combining other materials, scientists can develop new hybrid materials that are malleable and respond in a particular way.

For instance, clay minerals are currently used to create plastics that are significantly lighter, stronger and more elastic than those without clay. In these materials, the clay minerals are present in multiple layers, Johnston said. This adds stability to the plastic; it melts at a higher temperature; it’s stronger. However, there is limited control over how bulk, multilayer clay and another substance mix.

"Mixing bulk forms of clay is not the same as working with an individual layer, which allows you to manipulate it and to place it where you want it," he said.

In order to produce, directly see and work with a single layer of clay, Johnston and Katholieke Universiteit Leuven colleagues started with a technique called a Langmuir-Blodgett Balance. This involved putting clay particles into water and then adding insoluble organic molecules that have a positively charged tip. As the organic molecules float on the water surface, they attract and bind to the negatively charged clay.

The researchers used a Langmuir trough to force these combined particles into a line. This is akin to ping-pong balls floating in a pool of water and then compressing the water so all the balls are together, Johnston said. Next the scientists inserted a crystal into the water that would attract floating molecules. When the crystal was pulled out of the water, the molecules coated its surface, forming a film.

In order to detect the single layer of clay film, the scientists used infrared techniques, effective because clays absorb infrared light. They then used an atomic force microscope to see the hybrid film.

The investigators plan to continue their research by exploring different ways of making the hybrid films and the types of functionality that can be added or built into the films.

The study’s lead author is Robin Ras, a Katholieke Universiteit (K.U.) Leuven doctoral student in the Center for Surface Chemistry and Catalysis. The other authors are Robert Schoonheydt, K.U. Agricultural and Applied Biological Sciences Department dean and director of the Center for Surface Chemistry and Catalysis; Elias Franses, Purdue professor of chemical engineering; and K.U. Leuven scientists R. Ramaekers, G. Maes, P. Foubert, and F. De Schryver.

The Fund for Scientific Research-Flanders, a bilateral agreement Flanders-Hungary grant and the U.S. Department of Agriculture National Research Initiative provided funding for this work. Johnston also received a K.U. Leuven Fellowship.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Source: Cliff Johnston, (765) 496-1716, clays@purdue.edu

Ag Communications: (765) 494-2722; Beth Forbes, bforbes@aes.purdue.edu;

Susan A. Steeves | Purdue News
Further information:
http://news.uns.purdue.edu/html4ever/030415.Johnston.nanoclay.html
http://www.agriculture.purdue.edu/AgComm/public/agnews/
http://www.nano.gov/

More articles from Materials Sciences:

nachricht Move over, Superman! NIST method sees through concrete to detect early-stage corrosion
27.04.2017 | National Institute of Standards and Technology (NIST)

nachricht Control of molecular motion by metal-plated 3-D printed plastic pieces
27.04.2017 | Ecole Polytechnique Fédérale de Lausanne

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>