Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > 2 for 1: Simultaneous size and electrochemical measurement of nanomaterials

Schematic of NIST's "eSANS" (electrochemical Small-Angle Neutron Scattering) cell. A highly porous, sponge-like carbon electrode maximizes surface area for electrochemical reactions while structural details like particle size and configuration are measured using neutron scattering (image at left).

Credit: Prabhu/NIST
Schematic of NIST's "eSANS" (electrochemical Small-Angle Neutron Scattering) cell. A highly porous, sponge-like carbon electrode maximizes surface area for electrochemical reactions while structural details like particle size and configuration are measured using neutron scattering (image at left).

Credit: Prabhu/NIST

Abstract:
Researchers at the National Institute of Standards and Technology (NIST) have done a mash-up of two very different experimental techniques—neutron scattering and electrochemical measurements—to enable them to observe structural changes in nanoparticles as they undergo an important type of chemical reaction. Their recently published technique* allows them to directly match up particle size, shape and agglomeration with the "redox" chemical properties of the particles. The measurements are important both for the design of nanoparticles for particular applications and for toxicology studies.

2 for 1: Simultaneous size and electrochemical measurement of nanomaterials

Gaithersburg, MD | Posted on March 7th, 2012

Nanoparticles present unique engineering challenges—and opportunities—because their extremely small size can give them physical properties quite unlike those they have in bulk quantities. The challenge for materials scientists is to determine just what those changes are and how they relate to particle size and structure.

The NIST team was interested in the oxidation-reduction—redox— properties of zinc oxide nanoparticles, which are used or being considered for a wide variety of applications ranging from sunscreens and antibacterial coatings to semiconductor and photoelectronic devices.

Redox reactions are one of the major divisions of chemical reactions, those that involve a transfer of electrons from one atom or molecule to another. Redox properties determine the path a chemical reaction will take. "They are the drivers of many biological processes," explains NIST materials researcher Vivek Prabhu. "There are many biochemical reactions that are well-defined oxidation-reduction reactions. There are tables of these. But there are no such tables that we know of on how nanoparticles can affect those reactions."

The NIST team knew they could monitor the size, shape and dispersion of nanoparticles in solution using SANS—small-angle neutron scattering. The scattering patterns from a SANS instrument, says Prabhu, give you not only those details but structural information about the solution itself, the size distribution of the particles and whether they clump together, all in "real" time as the experiment progresses.

Redox properties, on the other hand, are measured in electrochemical cells that are essentially half of a battery. Voltage and the amount of current flowing through the primary electrode depend on the reaction redox potential and the concentration of the test material.

The problem, Prabhu explains, is that SANS measures things in bulk, in a volume of space, but, "An electrochemical experiment is a very local experiment—it happens at an interface. What we needed was to maximize the interface." The answer, contributed by his partner, Vytas Reipa, is an exotic material called reticulated glassy carbon. "Like a very stiff household sponge or scouring pad made of pure carbon," Prabhu explains. The porous carbon electrode turned out to be an ideal terminal—lots of surface area to serve as a reaction interface; nearly transparent to neutrons, so it doesn't contribute much background noise; and best of all, it works well in water, enabling the study of nanoparticles in aqueous solutions, critical for biological reactions.

A big advantage of the "eSANS" technique, Prabhu says, is its generality. "You can apply our method to nearly any dispersed material that is of interest to redox chemistry—polymers, redox proteins, nucleic acids—at this nanoscale. Small polymer chains, for example. You can't really see them with electron microscopy, you can with neutrons."

* V.M. Prabhu and V. Reipa. In situ electrochemical small-angle neutron scattering (eSANS) for quantitative structure and redox properties of nanoparticles. J. Phys. Chem. Lett. 2012, 3, 646-650 dx.doi.org/10.1021/jz300124t.

####

For more information, please click here

Contacts:
Michael Baum

301-975-2763

Copyright © National Institute of Standards and Technology (NIST)

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

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Harris & Harris Group Continues Its Blog Series to Highlight Most Impactful Portfolio Companies With Champions Oncology, Inc. April 17th, 2014

'Life Redesigned: The Emergence of Synthetic Biology' Lecture at Brookhaven Lab on Wednesday, April 30: Biomedical Engineer James Collins to Speak for BSA Distinguished Lecture Series April 16th, 2014

ECHA Planning Workshop on Regulatory Challenges in the Risk Assessment of Nanomaterials April 16th, 2014

Laboratories

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

'Life Redesigned: The Emergence of Synthetic Biology' Lecture at Brookhaven Lab on Wednesday, April 30: Biomedical Engineer James Collins to Speak for BSA Distinguished Lecture Series April 16th, 2014

Govt.-Legislation/Regulation/Funding/Policy

'Life Redesigned: The Emergence of Synthetic Biology' Lecture at Brookhaven Lab on Wednesday, April 30: Biomedical Engineer James Collins to Speak for BSA Distinguished Lecture Series April 16th, 2014

ECHA Planning Workshop on Regulatory Challenges in the Risk Assessment of Nanomaterials April 16th, 2014

UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Relieving electric vehicle range anxiety with improved batteries: Lithium-sulfur batteries last longer with nanomaterial-packed cathode April 16th, 2014

Discoveries

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Scientists observe quantum superconductor-metal transition and superconducting glass: A team including MIPT physicist observed quantum superconductor-metal transition and superconducting glass April 16th, 2014

UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Announcements

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Harris & Harris Group Continues Its Blog Series to Highlight Most Impactful Portfolio Companies With Champions Oncology, Inc. April 17th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Energy Research Facility Construction Project at Brookhaven Lab Wins U.S. Energy Secretary's Achievement Award April 16th, 2014

Tools

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Malvern reports on the publication of the 1000th peer-reviewed paper to cite NanoSight’s Nanoparticle Tracking Analysis, NTA April 16th, 2014

JPK announces expansion of its global sales and service activities in China and USA April 15th, 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