Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Bio-enabled, Surface-mediated Approach Produces Nanoparticle Composites

Georgia Tech researcher Eugenia Kharlampieva studies the properties of composite materials containing silk and metallic nanoparticles. (Georgia Tech Photo: Gary Meek)
Georgia Tech researcher Eugenia Kharlampieva studies the properties of composite materials containing silk and metallic nanoparticles. (Georgia Tech Photo: Gary Meek)

Abstract:
Thin Films of Silk Produce and Combine with Metallic Particles

Bio-enabled, Surface-mediated Approach Produces Nanoparticle Composites

Atlanta, GA | Posted on August 20th, 2009

Using thin films of silk as templates, researchers have incorporated inorganic nanoparticles that join with the silk to form strong and flexible composite structures that have unusual optical and mechanical properties. This bio-enabled, surface-mediated approach mimics the growth and assembly processes of natural materials, taking advantage of the ability of biomolecules to chemically reduce metal ions to produce nanoparticles—without harsh processing conditions.

Less than 100 nanometers thick, silk-silver nanoparticle composite films formed in this process can be used as flexible mirrors. The technique could also be used to create films that reflect light in specific wavelengths, anti-microbial coatings, thin film sensors, self-cleaning coatings, catalytic materials and potentially even flexible photovoltaic cells.

"We are taking advantage of biological molecules that have the ability to bind metallic ions of silver or gold from solution," said Vladimir Tsukruk, a professor in the Georgia Tech School of Materials Science and Engineering. "These molecules can create mono-dispersed metallic nanoparticles of consistent sizes under ambient conditions—at room temperature and in a water-based environment without high vacuum or high temperatures."

Sponsored by the Air Force Office of Scientific Research and the Air Force Research Laboratory, the research was described August 19 at the Fall 2009 National Meeting of the American Chemical Society.

The nanoparticles produced range in size from four to six nanometers in diameter, surrounded by a biological shell of between one and two nanometers. The silk template permits good control of the nanoparticle placement, creating a composite with equally dispersed particles that remain separate. The optical properties of the resulting film depend on the nanoparticle material and size.

"This system provides very precise control over nanoparticle sizes," said Eugenia Kharlampieva, a postdoctoral researcher in Tsukruk's laboratory. "We produce well-defined materials without the problem of precipitation, aggregation or formation of large crystals. Since the silk fibroin is mono-dispersed, we can create uniform domains within the template."

Fabrication of the nanocomposites begins by dissolving silk cocoons and making the resulting fibroin water soluble. The silk is then placed onto a silicon substrate using a spin-coating technique that produces multiple layers of thin film that is then patterned into a template using a nanolithography technique.

"Because silk is a protein, we can control the properties of the surface and design different kinds of surfaces," explained Kharlampieva. "This surface-mediated approach is flexible at producing different shapes. We can apply the method to coat any surface we want, including objects of complex shapes."

Next, the silk template is placed in a solution containing ions of gold, silver, or other metal. Over a period of time ranging from hours to days, nanoparticles form within the template. The relatively long growth process, which operates at room temperature and neutral pH in a water-based environment, allows precise control of the particle size and spacing, Tsukruk notes.

"We operate at conditions that are suitable for biological activities," he explained. "No reducing agents are required to produce the particles because the biomolecules serve as reducing agents. We don't add any chemicals that could be toxic to the protein."

Use of these mild processing conditions could reduce the cost of producing the composites and their potential environmental impact. When dried, the resulting silk-nanoparticle film has high tensile strength, high elasticity and toughness.

"Silk is almost as strong as Kevlar, but it can be deformed by 30 percent without breaking," said Tsukruk. "The silk film is very robust, with a complicated structure that you don't find in synthetic materials."

For the future, the researchers plan to use the bio-assisted, surface-mediated technique to produce nanoparticles from other metals. They also hope to combine different types of particles to create new optical and mechanical properties.

"If we combine gold-binding and silver-binding peptides, we can make composites that will include a mixture of gold and silver nanoparticles," said Kharlampieva. "Each particle will have its own properties, and combining them will create more interesting composite materials."

The researchers also hope to find additional applications for the films in such areas as photovoltaics, medical technology and anti-microbial films that utilize the properties of silver nanoparticles.

Beyond Tsukruk and Kharlampieva, the research team has included Dmitry Zimnistky, Maneesh Gupta and Kathryn Bergman of Georgia Tech; David Kaplan of the Department of Biomedical Engineering at Tufts University, and Rajesh Naik of the Materials and Manufacturing Directorate of the Air Force Research Laboratory at Wright-Patterson Air Force Base.

"Nanomaterials grown under environmentally friendly conditions can be as good as synthetic materials that are produced under harsh conditions," Tsukruk added. "This technique allows us to grow very useful materials under natural conditions."

####

About Georgia Institute of Technology
The Georgia Institute of Technology is one of the nation's premier research universities. Ranked seventh among U.S. News & World Report's top public universities, Georgia Tech's more than 19,000 students are enrolled in its Colleges of Architecture, Computing, Engineering, Liberal Arts, Management and Sciences. Tech is among the nation's top producers of women and African-American engineers. The Institute offers research opportunities to both undergraduate and graduate students and is home to more than 100 interdisciplinary units plus the Georgia Tech Research Institute.

For more information, please click here

Contacts:
Media Relations Contacts
John Toon
404-894-6986


Abby Vogel
404-385-3364


Technical Contact
Vladimir Tsukruk
404-894-6081

Copyright © Georgia Institute of Technology

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 News Press

News and information

Harris & Harris Group to Host Conference Call on Second-Quarter 2014 Financial Results on August 15, 2014 July 23rd, 2014

UCF Nanotech Spinout Developing Revolutionary Battery Technology: Power the Next Generation of Electronics with Carbon July 23rd, 2014

Deadline Announced for Registration in 7th Int'l Nanotechnology Festival in Iran July 23rd, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Thin films

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Even geckos can lose their grip July 9th, 2014

Shrinky Dinks close the gap for nanowires July 1st, 2014

Micro-manufacturing breakthrough is wired for sound June 24th, 2014

Nanomedicine

Researchers create vaccine for dust-mite allergies Main Page Content: Vaccine reduced lung inflammation to allergens in lab and animal tests July 22nd, 2014

NIST shows ultrasonically propelled nanorods spin dizzyingly fast July 22nd, 2014

SentiMag® Now Available in Australia and New Zealand July 21st, 2014

More than glitter: Scientists explain how gold nanoparticles easily penetrate cells, making them useful for delivering drugs July 21st, 2014

Sensors

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Iranian Scientists Use Nanosensors to Achieve Best Limit for Early Cancer Diagnosis July 19th, 2014

Announcements

Harris & Harris Group to Host Conference Call on Second-Quarter 2014 Financial Results on August 15, 2014 July 23rd, 2014

UCF Nanotech Spinout Developing Revolutionary Battery Technology: Power the Next Generation of Electronics with Carbon July 23rd, 2014

Deadline Announced for Registration in 7th Int'l Nanotechnology Festival in Iran July 23rd, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Environment

Researchers Use Various Zinc Oxide Nanostructures to Boost Efficiency of Water Purification Process July 13th, 2014

Using Sand to Improve Battery Performance: Researchers develop low cost, environmentally friendly way to produce sand-based lithium ion batteries that outperform standard by three times July 8th, 2014

Development of an interactive tool for the implementation of environmental legislation for nanoparticles manufacturers July 4th, 2014

Up in Flames: Evidence Confirms Combustion Theory: Berkeley Lab and University of Hawaii research outlines the story of soot, with implications for cleaner-burning fuels July 1st, 2014

Energy

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2014 conference July 8th, 2014

Industrial

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

Non-Enzyme Sensor Detects Lead, Hydrogen Peroxide July 10th, 2014

New Method Introduced for Synthesis of Hydroxyapatite Nanoparticles July 5th, 2014

Making dreams come true: Making graphene from plastic? July 2nd, 2014

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Researchers create vaccine for dust-mite allergies Main Page Content: Vaccine reduced lung inflammation to allergens in lab and animal tests July 22nd, 2014

EPFL Research on the use of AFM based nanoscale IR spectroscopy for the study of single amyloid molecules wins poster competition at Swiss Physics Society meeting July 22nd, 2014

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

Albany NanoCollege Faculty Member Selected as Editor-in-Chief of the Prestigious Journal of Electronic Materials July 1st, 2014

Nanobiotechnology

Production of Non-Virus Nanocarriers with Highest Amount of Gene Delivery July 17th, 2014

Physicists Use Computer Models to Reveal Quantum Effects in Biological Oxygen Transport: The team solved a long-standing question by explaining why oxygen – and not deadly carbon monoxide – preferably binds to the proteins that transport it around the body. July 17th, 2014

Tiny DNA pyramids enter bacteria easily -- and deliver a deadly payload July 9th, 2014

Artificial cilia: Scientists from Kiel University develop nano-structured transportation system July 4th, 2014

Solar/Photovoltaic

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

Making dreams come true: Making graphene from plastic? July 2nd, 2014

Shrinky Dinks close the gap for nanowires July 1st, 2014

New Study Raises Possibility of Production of P-Type Solar Cells July 1st, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE