Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Collaboration Leads to Simpler Method for Building Varieties of Nanocrystal Superlattices

Electron microscopes show the preparation of BNSL membranes on the left, with higher magnification shown on the right. (Credit: University of Pennsylvania)
Electron microscopes show the preparation of BNSL membranes on the left, with higher magnification shown on the right. (Credit: University of Pennsylvania)

Abstract:
Collaboration by chemists, physicists and materials scientists at the University of Pennsylvania has created a simple and inexpensive method to rapidly grow centimeter-scale membranes of binary nanocrystal superlattices, or BNSLs, by crystallizing a mixture of nanocrystals on a liquid surface.

Collaboration Leads to Simpler Method for Building Varieties of Nanocrystal Superlattices

Philadelphia, PA | Posted on July 22nd, 2010

The study demonstrates a new and spontaneous way to grow long-range-ordered BNSL membranes with rigorous control of nanocrystal size, shape and concentration by combining two types of nanocrystals and assembling them during a drying stage at the surface of a liquid under normal conditions.

The method overcomes several limitations of the existing assembly strategies and produces large, free-standing membranes that can be transferred to any desired substrate such as silicon wafers, glass slides and plastic substrates, allowing the nanocryatalline films to be introduced at any stage in the device fabrication process.

The team demonstrated the potential for integrating these novel materials by growing millimeter-scale superlattice membranes containing iron oxide nanocrystals of two different sizes and incorporating the membranes into magnetoresistive devices. Measurements showed that the magnetoresistance of the resulting device was dependent on the structure of the BNSL and therefore controllable.

The physical properties intrinsic in these nanocrystals -- nanometer sized crystalline building blocks offer a modern twist on the studies of interfacial assembly that reach as far back as Penn founder Benjamin Franklin and his studies of oil spreading on water in the 1770s.

Single and multi-component nanocrystal films are already under intense investigation by researchers as enablers of novel optical technologies that range from low-cost solar cells, light-emitting diodes and photo detectors and also in electronic systems that include field-effect transistors and solid-state thermoelectric coolers and generators and magnetic technologies that include magnetic recording materials and magnetic sensors and even as tailored electrocatalytic and photocatalytic films.

Co-assembly of two types of nanocrytals into BNSLs provides a low-cost, modular route to program the self assembly of materials with a precisely controlled combinations of properties. Advances in these complex interfacial assemblies and improvements in the transfer of single-component nanocrystal membranes in the past few years have heightened anticipation that this control could be extended to much more complex systems.

This Penn study establishes a route to free-standing large-area BNSLs membranes with the added ability to laminate them on any arbitrary substrate.

"Fundamentally, growing BNSLs on a liquid surface will shed light on the mechanisms of multi-component nanocrystal assembly, which are critical to new concepts in self-assembly based nanomanufacturing," said Christopher B. Murray, the Richard Perry University Professor of Chemistry and Material Science and Engineering at Penn.

The research, funded by the U.S. Army Research Office and a National Science Foundation Materials Research Science and Engineering Centers Award, is published in this week's Nature.

Existing strategies for growing BNSLs involve a more complex process of evaporating a two-nanocrystal solution on a solid substrate under carefully regulated temperature and pressure that influence BNSL formation. The method suffers from several limitations, most notably a limited choice of substrate, nucleation of irregular micrometer-sized, isolated islands of BNSLs on the substrates and an inability to transfer them once formed.

"Given the fact that this novel assembly strategy is general for different nanocrystal combinations, we anticipate that membranes of quasicrystalline BNSLs and ternary nanocrystal superlattices will also be grown by this method, greatly expanding the systems that can be explored" Murray said. "Our dream is to program the organization of materials on all lengths scales for nanometers to millimeters combining the desirable physical properties multiple nanoscale systems. Fundamentally we are focused on identifying, understanding and optimizing new synergistic interactions in nanomaterials and in exploiting these emergent properties in new devices and systems."

This interdisciplinary study was conducted by Murray and Angang Dong in the Department of Chemistry in the School of Arts and Sciences and the Department of Materials Science and Engineering in the School of Engineering and Applied Science, Jun Chen of Materials Science and Engineering and Patrick M. Vora and James M. Kikkawa of the Department of Physics and Astronomy in SAS.

Additional information on research funded by the National Science Foundation Materials Research Science and Engineering Centers is available at www.mrsec.org

####

For more information, please click here

Contacts:
Media Contact:
Jordan Reese

215-573-6604

Copyright © University of Pennsylvania

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

Electric-car battery materials could harm key soil bacteria February 11th, 2016

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Academic/Education

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

COD Grad Begins Postdoctoral Fellow at Harvard University: Marsela Jorgolli's Passion for Physics Has Led to a Decade of Academic Research That Continues at Harvard University as a Postdoctoral Fellow February 2nd, 2016

Heriot-Watt's Institute of Photonics & Quantum Sciences uses the Deben Microtest 2 kN tensile stage to characterise ceramics and engineering plastics January 21st, 2016

Multiple uses for the JPK NanoWizard AFM system in the Smart Interfaces in Environmental Nanotechnology Group at the University of Illinois at Urbana-Champaign January 20th, 2016

Self Assembly

New type of nanowires, built with natural gas heating: UNIST research team developed a new simple nanowire manufacturing technique February 1st, 2016

Researchers develop completely new kind of polymer: Hybrid polymers could lead to new concepts in self-repairing materials, drug delivery and artificial muscles January 30th, 2016

Polymer nanowires that assemble in perpendicular layers could offer route to tinier chip components January 23rd, 2016

Nanodevice, build thyself: Researchers in Germany studied how a multitude of electronic interactions govern the encounter between a molecule called porphine and copper and silver surfaces January 18th, 2016

Announcements

Research reveals carbon films can give microchips energy storage capability: International team from Drexel University and Paul Sabatier University reveals versatility of carbon films February 11th, 2016

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Research partnerships

Research reveals carbon films can give microchips energy storage capability: International team from Drexel University and Paul Sabatier University reveals versatility of carbon films February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Chemical cages: New technique advances synthetic biology February 10th, 2016

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

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







Car Brands
Buy website traffic