Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Researchers create freestanding nanoparticle films without fillers

Assistant Professor of Physics James Dickerson (left) and graduate student Saad Hasan. (Photo by Daniel DuBois)
Assistant Professor of Physics James Dickerson (left) and graduate student Saad Hasan. (Photo by Daniel DuBois)

Abstract:
Nanoparticle films are no longer a delicate matter: Vanderbilt physicists have found a way to make them strong enough so they don't disintegrate at the slightest touch.

Researchers create freestanding nanoparticle films without fillers

Posted on June 9th, 2009

In the last 25 years, ever since scientists figured out how to create nanoparticles - ultrafine particles with diameters less than 100 nanometers - they have come up with a number of different methods to mold them into thin films which have a variety of interesting potential applications ranging from semiconductor fabrication to drug delivery, solid state lighting to flexible television and computer displays.

Until now these films have had a common problem: lack of cohesion. Nanoparticles typically consist of an inorganic core coated with a thin layer of organic molecules. These particles are not very sticky so they don't form coherent thin films unless they are encapsulated in a polymer coating or mixed with molecules called chemical "cross-linkers" that act like glue to stick the nanoparticles together.

"Adding this extra material can complicate the fabrication of nanoparticle films and make them more expensive. In addition, the added material, usually a polymer, can modify the physical properties that make these films so interesting," says James Dickerson, assistant professor of physics at Vanderbilt, who headed the research group that developed freestanding nanoparticle films without any additives.

The properties of the new films and the method that the researchers use to create them is described in the article "Sacrificial layer electrophoretic deposition of freestanding multilayered nanoparticle films" published online in the journal Chemical Communications on May 27, 2009.

"Our films are so resilient that we can pick them up with a pair of tweezers and move them around on a surface without tearing," says Dickerson. "This makes it particularly easy to put them into microelectronic devices, such as computer chips."

Dickerson considers the most straightforward applications for his films to be in semiconductor manufacturing to aid in the continued miniaturization of digital circuitry and in the production of flexible television and computer screens.

A key component in the transistors in integrated circuits is an insulating layer that separates the gate, which turns current flow on and off, from the channel through which the current flows. Traditionally, semiconductor manufacturers have used silicon dioxide for this purpose. As transistors have shrunk, however, they have been forced to make this layer thinner and thinner until they reached the point where electrons leak through and sap the power from the device. This has led semiconductor manufacturers to retool their process to use "high-k" dielectric materials, such as hafnium oxide, because they have much higher electrical resistance.

"We have made high-k nanoparticle films that could be cheaper and more effective than the high-k materials the manufacturers are currently using," Dickerson says.

In addition, the physicist argues that the films have properties that make them ideal for flexible television and computer screens. They are very flexible and don't show any signs of cracking when they are flexed repeatedly. They are also made using a technique called electrophoretic deposition (EPD) that is well suited for creating patterned material and is compatible with fluorescent materials that can form the red, green and blue pixels used in flat panel television screens and computer displays.

EDP is a wet method. Nanoparticles are placed in a solution along with a pair of electrodes. When an electric current is applied, it creates an electrical field in the liquid that attracts the nanoparticles, which coat the electrodes. Using colloids, mixtures with particles 10 to 1,000 times larger than nanoparticles, EDP is widely used to apply coatings to complex metal parts such as automobile bodies, prosthetic devices, appliances and beverage containers. It is only recently that researchers like Dickerson have begun applying the technique to nanoparticles.

"The science of colloidal EDP is well known but the particles are substantially larger than the solvent molecules. Many nanoparticles, however, are about the same size as the solvent molecules, which makes the process considerably more complicated and difficult to control," Dickerson explains.

To get the method to work, in fact, Dickerson and his colleagues had to invent a new form of EDP, which they call sacrificial layer electrophoretic deposition. They added a spun-cast layer of polymer to the electrodes that serves as a pattern that organizes the nanoparticles as they are deposited. Then, after the deposition process is completed, they dissolve (sacrifice) the polymer layer to free the nanoparticle film.

According to the researchers, films made in this fashion stick together because the electrical field slams the nanoparticles into the film with sufficient force to pack the particles together tightly enough to allow naturally attractive inter-particle forces to bind the particles together.

So far the Dickerson group has used the technique to make films out of two different types of nanoparticles - iron oxide and cadmium selenide - and they believe the technique can be used with a wide variety of other nanoparticles.

"The technique is liberating because you can make these films from the materials you want and use them where you want," Dickerson says.

The co-authors on the paper are graduate students Saad A. Hasan and Dustin W. Kavich. The research was funded by a grant from Vanderbilt University.

####

About Vanderbilt University
Vanderbilt University is a center for scholarly research, informed and creative teaching, and service to the community and society at large. Vanderbilt will uphold the highest standards and be a leader in the

* quest for new knowledge through scholarship,
* dissemination of knowledge through teaching and outreach,
* creative experimentation of ideas and concepts.

In pursuit of these goals, Vanderbilt values most highly

* intellectual freedom that supports open inquiry,
* equality, compassion, and excellence in all endeavors.

Contacts:
Media Contact
David F. Salisbury
(615) 322-NEWS

Copyright © Vanderbilt University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Multimedia Version of article

Related News Press

Physics

Donuts, math, and superdense teleportation of quantum information May 29th, 2015

OSU researchers prove magnetism can control heat, sound: Team leverages OSC services to help confirm, interpret experimental findings May 29th, 2015

Two UCSB Professors Receive Early Career Research Awards: The Department of Energy’s award for young scientists acknowledges UC Santa Barbara’s standing as a top tier research institution May 29th, 2015

How spacetime is built by quantum entanglement: New insight into unification of general relativity and quantum mechanics May 28th, 2015

Squeezed quantum cats May 28th, 2015

Display technology/LEDs/SS Lighting/OLEDs

SouthWest NanoTechnologies Introduces AgeNT™ Transparent Conductor System at SID Display Week, Booth #543 May 28th, 2015

Statement by QD Vision regarding European Parliament’s Vote on Cadmium-Based Quantum Dots May 20th, 2015

Thin films

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Possible Futures

Global Carbon Nanotubes (CNT) Market Expected To Reach USD 3.42 Billion By 2022 May 29th, 2015

Global Nano-Enabled Packaging Market For Food and Beverages Will Reach $15.0 billion in 2020 May 26th, 2015

Simulations predict flat liquid May 21st, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

Chip Technology

Stanford breakthrough heralds super-efficient light-based computers: Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires May 29th, 2015

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Collaboration could lead to biodegradable computer chips May 28th, 2015

Physicists solve quantum tunneling mystery: ANU media release: An international team of scientists studying ultrafast physics have solved a mystery of quantum mechanics, and found that quantum tunneling is an instantaneous process May 27th, 2015

Nanomedicine

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Arrowhead to Present at Jefferies 2015 Healthcare Conference May 27th, 2015

Seeing the action: UCSB researchers develop a novel device to image the minute forces and actions involved in cell membrane hemifusion May 27th, 2015

Nanotechnology identifies brain tumor types through MRI 'virtual biopsy' in animal studies: If results are confirmed in humans, tumor cells could someday be diagnosed by MRI imaging and treated with tumor-specific IV injections; new NIH grant will fund future study May 27th, 2015

Nanoelectronics

Technology for Tomorrow’s Market Opportunities and Challenges: LetiDays Grenoble Presents the Possibilities: June 24-25 Event Includes Focus on IoT-Augmented Mobility and Leti’s Latest Results on Silicon Technologies, Sensors, Health Applications and Smart Cities May 27th, 2015

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Discoveries

Stanford breakthrough heralds super-efficient light-based computers: Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires May 29th, 2015

Donuts, math, and superdense teleportation of quantum information May 29th, 2015

OSU researchers prove magnetism can control heat, sound: Team leverages OSC services to help confirm, interpret experimental findings May 29th, 2015

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Announcements

Stanford breakthrough heralds super-efficient light-based computers: Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires May 29th, 2015

Donuts, math, and superdense teleportation of quantum information May 29th, 2015

OSU researchers prove magnetism can control heat, sound: Team leverages OSC services to help confirm, interpret experimental findings May 29th, 2015

Two UCSB Professors Receive Early Career Research Awards: The Department of Energy’s award for young scientists acknowledges UC Santa Barbara’s standing as a top tier research institution May 29th, 2015

Nanobiotechnology

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Seeing the action: UCSB researchers develop a novel device to image the minute forces and actions involved in cell membrane hemifusion May 27th, 2015

Nanotechnology identifies brain tumor types through MRI 'virtual biopsy' in animal studies: If results are confirmed in humans, tumor cells could someday be diagnosed by MRI imaging and treated with tumor-specific IV injections; new NIH grant will fund future study May 27th, 2015

Who needs water to assemble DNA? Non-aqueous solvent supports DNA nanotechnology May 27th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project