Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Nanometer-thick clay may yield groundbreaking technology


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,

Source: Cliff Johnston, (765) 496-1716,

Ag Communications: (765) 494-2722; Beth Forbes,;

Susan A. Steeves | Purdue News
Further information:

More articles from Materials Sciences:

nachricht For graphite pellets, just add elbow grease
23.03.2018 | Rice University

nachricht Sensitive grip
23.03.2018 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>