Navigation Links
Penn collaboration leads to simpler method for building varieties of nanocrystal superlattices
Date:7/23/2010

PHILADELPHIA - 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.

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."


'/>"/>

Contact: Jordan Reese
jreese@upenn.edu
215-573-6604
University of Pennsylvania
Source:Eurekalert  

Related biology technology :

1. X-Chem and Roche Enter Into Drug Discovery Collaboration and License Agreement
2. Aeterna Zentaris Announces Collaboration with Almac to Develop Therapy and Companion Diagnostic in Cancer
3. Mount Sinai Medical Center Drives Genomic Research Collaboration with Isilon Scale-out NAS
4. Heptares Therapeutics Extends Multi-FTE Chemistry Collaboration With Oxygen Healthcare (O2h)
5. Penn-led collaboration mimics library of bio-membranes for use in nanomedicine, drug delivery
6. Educating the Marketplace Through Collaborations with Patient Advocacy Groups
7. Elekta / Mitsubishi Electric Collaboration Helps Japans Gunma University Heavy Ion Medical Center Launch Advanced Carbon Ion Therapy for Treating Cancer
8. Cheaper drugs, vaccines forecast as collaborations grow between developing countries biotech firms
9. iCyt Unveils New Flow Cytometry Products in Collaboration with Sony at CYTO2010
10. Boehringer Ingelheim and Micromet Announce Global Collaboration for Multiple Myeloma BiTE Antibody
11. S*BIO and Onyx Pharmaceuticals Announce Expanded Development Collaboration for JAK2 Inhibitors
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Penn collaboration leads to simpler method for building varieties of nanocrystal superlattices
(Date:2/4/2016)... ... February 04, 2016 , ... Franz Inc. , an ... technology has been recognized As “ Best in Semantic Web Technology - USA ... Corporate America, it’s our priority to showcase prominent professionals who are excelling in ...
(Date:2/3/2016)... , Feb. 3, 2016  With the ... patent cliff that is underway, therapies such as ... for a whole host of indications are in ... aid in the development and production of these ... poor quality and high costs, novel approaches and ...
(Date:2/3/2016)... ... February 03, 2016 , ... ProMIS Neurosciences is currently in ... to misfolded, propagating strains of Amyloid beta involved in Alzheimer’s disease. The Company ... , Following on from the first misfolded Amyloid beta target announced on Nov. ...
(Date:2/3/2016)... , ... February 03, 2016 , ... ... to aid in the rapid development and ongoing quality control of molecular assays ... outbreak is extremely high,” Dr. Gregory R. Chiklis, President and CEO of ZeptoMetrix, ...
Breaking Biology Technology:
(Date:1/18/2016)... , Jan. 18, 2016  Extenua Inc., ... that simplifies the use and access of ubiquitous ... go-to-market partnership with American Cyber.  ... extensive experience leading transformational C4ISR and Cyber initiatives ... integrating the latest proven technology solutions," said ...
(Date:1/13/2016)... , January 13, 2016 /PRNewswire/ ... announced the addition of the  "India ... Estimation & Forecast (2015-2020)"  report ... http://www.researchandmarkets.com/research/7h6hnn/india_biometrics ) has announced the addition ... Identification Market - Estimation & Forecast ...
(Date:1/8/2016)... and MANCHESTER, United Kingdom , Jan. 8, ... of innovative sensor-based diagnostic products, today announced the closing of ... and existing investors.  Proceeds from the financing will be used ... a hand-held device for detecting early-stage pressure ulcers. ... after receiving CE Mark approval. The device,s introduction ...
Breaking Biology News(10 mins):