Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High-Fidelity Patterns Form Spontaneously When Solvent Evaporates

03.03.2005


Resembling neatly stacked rows of driftwood abandoned by receding tides, particles left by a confined, evaporating droplet can create beautiful and complex patterns. The natural, pattern-forming process could find use in fields such as nanotechnology and optoelectronics.

"A lot of work in nanotechnology has been directed toward the bottom-up imposition of patterns onto materials," said Steve Granick, a professor of materials science, chemistry and physics at the University of Illinois at Urbana-Champaign. "We found that beautiful patterns of high fidelity and regularity could form naturally and spontaneously, simply by allowing a drop to evaporate in a confined geometry."

Granick and former postdoctoral research associate Zhiqun Lin (now a professor of materials science at Iowa State University) describe their work in a paper that has been accepted for publication in the Journal of the American Chemical Society, and posted on its Web site. Funding was provided by the U.S. Department of Energy.



To produce the patterns, Granick and Lin began by gluing two small mica sheets to cylindrical mounts. With the cylinders at right angles, a droplet of volatile solution containing small polymer chains was inserted between the curved mica sheets. The sheets were then brought into contact and left undisturbed until evaporation was complete.

Because evaporation in this geometry is restricted to the edge of the droplet, the process results in hundreds of concentric rings with regular spacing, very much resembling a miniature archery target. Each ring - composed of polymer chains abandoned as the solvent receded - is several nanometers high and several microns wide.

The droplet evaporates in a jerky, stick-slip fashion, said Granick, who also is a researcher at the Frederick Seitz Materials Research Laboratory and at the Beckman Institute for Advanced Science and Technology.

"While the droplet is sticking to the surface, a ring of polymer is deposited," he said. "As evaporation continues, tension builds in the droplet. Eventually the droplet jerks to a new position, the tension is temporarily relieved, and another ring is deposited."

The simple evaporative process could be used to form patterns with many other materials, such as electrically conducting polymers, nanoparticles and proteins. Pattern formation could be controlled by altering the size of the material, changing the solvent, or modifying the surfaces.

"The pattern emerges spontaneously from the geometry in which we put the droplet," Granick said. "This means we could make other kinds of patterns by using different geometries or surfaces with tailored wettability."

James E. Kloeppel | News Bureau
Further information:
http://www.uiuc.edu

More articles from Materials Sciences:

nachricht New material could lead to erasable and rewriteable optical chips
07.12.2016 | University of Texas at Austin

nachricht Porous crystalline materials: TU Graz researcher shows method for controlled growth
07.12.2016 | Technische Universität Graz

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>