Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Unraveling Intricate Interactions, One Molecule at a Time

This model structure illustrates the bonding of bipyridine to the rough gold surface through direct nitrogen-gold chemical bonding and indirect van der Waals bonding.
This model structure illustrates the bonding of bipyridine to the rough gold surface through direct nitrogen-gold chemical bonding and indirect van der Waals bonding.

Abstract:
In key step towards design of better organic electronic devices, Columbia Engineering team makes first single-molecule measurement of van der Waals interactions at a metal-organic interface.

Unraveling Intricate Interactions, One Molecule at a Time

Upton, NY | Posted on August 12th, 2012

A team of researchers at Columbia Engineering, led by Applied Physics and Applied Mathematics Associate Professor Latha Venkataraman and in collaboration with Mark Hybertsen from the Center for Functional Nanomaterials at the U.S. Department of Energy's Brookhaven National Laboratory, has succeeded in performing the first quantitative characterization of van der Waals interactions at metal/organic interfaces at the single-molecule level.

In a study published online August 12 in the Advance Online Publication on Nature Materials's website, the team has shown the existence of two distinct binding regimes in gold-molecule-gold single-molecule junctions, using molecules containing nitrogen atoms at their extremities that are attracted to gold surfaces. While one binding mechanism is characterized by chemical interactions between the specific nitrogen and gold atoms, the other is dominated by van der Waals interactions between the molecule and the gold surface.

"A detailed understanding of van der Waals interactions is a key step towards design of organic electronic devices," says Sriharsha Aradhya, the study's lead author and a Ph.D. candidate working with Venkataraman. "Apart from the fundamental importance of these measurements, we are also excited about its applications. Understanding the effects of van der Waals interactions is tremendously important for creating and optimizing devices with organic building-blocks".

"Many proposals for future photovoltaic and flexible electronic devices are based on organic molecules because they are cost-effective," Venkataraman adds, "and scientists need to have a deeper understanding of these van der Waals interactions. Our work opens up the possibility of measuring and characterizing the strength of interaction between a variety of molecules and metallic surfaces a single-molecule at a time."

The forces of attraction between atoms and molecules come in different varieties and strengths, Aradhya explains. One of the most ubiquitous forms of attraction in nature is the van der Waals force. In contrast to specific interactions arising from bonding between atoms, van der Waals interactions represent non-specific interactions with subtler underpinnings. While originally intended to explain the apparent continuity between gaseous and liquid phases of matter, these forces have come to be recognized as an important aspect in answering such diverse questions as how does water boil inside a pressure cooker? How are geckos able to climb walls vertically? Or how can you control the organization of molecules for an organic LED smartphone display screen?

As devices like the latter become increasingly common, there has been a good deal of renewed interest in van der Waals interactions, known to lie at the heart of the structure and functionality in such devices. These interactions between organic molecules and metallic surfaces are central to a diverse range of phenomena such as catalysis of reactions, molecular electronic architectures, and molecular self-assembly in nature and engineered material. However, van der Waals interactions remain challenging to characterize directly at the fundamental, single-molecule level both in experiments and in theoretical calculations.

For this Columbia Engineering study, the researchers used their custom-built conducting atomic force microscope to make simultaneous measurements of force and conductance in single-molecule junctions. They combined their measurements with theoretical calculations and simulations, carried out in collaboration with Hybertsen at Brookhaven, in order to provide a unique quantitative measurement of the relative importance of specific and non-specific interactions at the single-molecule level, in a regime where both are comparable.

"In simple terms, conductance of the junction acts as a fingerprint of the structure," explains Aradhya. "At the same time, the measured force - especially the force needed to rupture the junction - can be used to deduce its mechanical properties."

While similar studies have been reported by a few research groups around the world, such precise studies have typically required the measurements to be carried out at very low temperatures and in high vacuum. Venkataraman's and Aradhya's experimental setup was optimized for very high sensitivities even at room temperature and ambient conditions. This allowed the team to perform thousands of individual single-molecule measurements, resulting in statistically robust results. The researchers then performed extensive density functional theory calculations to help them understand the mechanisms underlying their measurements.

"Taken together, this unique combination of our state-of-the-art experimental and theoretical efforts has resulted in this major progress in quantifying van der Waals interactions," Venkataraman says.

Future research, she adds, will include trying to control the interplay of van der Waals non-specific interactions with chemical modifications, in order to "achieve interesting functionality at the single-molecule level, which is an active area of research in our lab."

"We're very excited about this," she says, "as our efforts towards developing a reliable way to simultaneously measure force and conductance are yielding exciting new opportunities to relate structure, mechanics, and electronics at the single-molecule level."

As Hybertsen notes, "The development and validation of efficient theoretical models for the van der Waals interaction is still in its nascent stage. We expect that our work will also have an impact on this theoretical effort underway among many research groups around the globe to develop accurate treatment of van der Waals interactions."

The experiments were conceived by Aradhya and Venkataraman. The experimental tools and large dataset analysis techniques necessary for this study were developed by Aradhya, along with Michael Frei, a recent graduate of Venkataraman's lab. The modeling of the interactions and the calculations were conceived and executed by Hybertsen at Brookhaven.

This research was funded primarily by NSF (Career Award CHE-07-44185) and the Packard Foundation. The computational efforts at the Center for Functional Nanomaterials at Brookhaven National Laboratory were supported by the U.S. Department of Energy's Office of Science.

####

About Brookhaven National Laboratory
One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more at www.bnl.gov/newsroom , or follow Brookhaven Lab on Twitter, twitter.com/BrookhavenLab .

About Columbia Engineering:

Columbia University's Fu Foundation School of Engineering and Applied Science, founded in 1864, offers programs in nine departments to both undergraduate and graduate students. With facilities specifically designed and equipped to meet the laboratory and research needs of faculty and students, Columbia Engineering (http://www.engineering.columbia.edu/) is home to NSF-NIH funded centers in genomic science, molecular nanostructures, materials science, and energy, as well as one of the world's leading programs in financial engineering. These interdisciplinary centers are leading the way in their respective fields while individual groups of engineers and scientists collaborate to solve some of modern society's more difficult challenges.

About Center for Functional Nanomaterials at Brookhaven National Laboratory:

The Center for Functional Nanomaterials (www.bnl.gov/cfn) at Brookhaven National Laboratory is one of five DOE funded Nanoscience Research Centers (nano.energy.gov/)

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

For more information, please click here

Contacts:
Columbia Engineering:
Holly Evarts
347-453-7408


Brookhaven National Laboratory:
Kay Cordtz
(631) 344-2719

or
Peter Genzer
(631) 344-3174

Copyright © Brookhaven National Laboratory

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

Physics

Searching for errors in the quantum world September 21st, 2018

News and information

Searching for errors in the quantum world September 21st, 2018

Viral RNA sensing: Optical detection of picomolar concentrations of RNA using switches in plasmonic chirality September 21st, 2018

UT engineers develop first method for controlling nanomotors: Breakthrough for nanotechnology as UT engineers develop first method for switching the mechanical motion of nanomotors September 21st, 2018

Nanobiotix: Update on Head and Neck Phase I/II Trial with NBTXR3 and Other program data presented at ImmunoRad 2018 September 20th, 2018

Laboratories

Cannibalistic materials feed on themselves to grow new nanostructures September 1st, 2018

A Novel Graphene Quantum Dot Structure Takes the Cake August 24th, 2018

Virginia Tech researchers develop novel process to 3D print one of the strongest materials on Earth August 23rd, 2018

Display technology/LEDs/SS Lighting/OLEDs

Environmentally friendly photoluminescent nanoparticles for more vivid display colors: Osaka University-led researchers created a new type of light-emitting nanoparticle that is made of ternary non-toxic semiconductors to help create displays and LED lighting with better colors t August 29th, 2018

Carbon in color: First-ever colored thin films of nanotubes created: A method developed at Aalto University, Finland, can produce large quantities of pristine single-walled carbon nanotubes in select shades of the rainbow; the secret is a fine-tuned fabrication process -- and a s August 29th, 2018

Govt.-Legislation/Regulation/Funding/Policy

UT engineers develop first method for controlling nanomotors: Breakthrough for nanotechnology as UT engineers develop first method for switching the mechanical motion of nanomotors September 21st, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Self Assembly

DNA drives design principles for lighter, thinner optical displays: Lighter gold nanoparticles could replace thicker, heavier layered polymers used in displaysí back-reflectors June 27th, 2018

Collaboration yields discovery of 12-sided silica cages June 20th, 2018

Self-assembling 3D battery would charge in seconds May 22nd, 2018

Engineered polymer membranes could be new option for water treatment May 6th, 2018

Discoveries

Searching for errors in the quantum world September 21st, 2018

Viral RNA sensing: Optical detection of picomolar concentrations of RNA using switches in plasmonic chirality September 21st, 2018

UT engineers develop first method for controlling nanomotors: Breakthrough for nanotechnology as UT engineers develop first method for switching the mechanical motion of nanomotors September 21st, 2018

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Announcements

Searching for errors in the quantum world September 21st, 2018

Viral RNA sensing: Optical detection of picomolar concentrations of RNA using switches in plasmonic chirality September 21st, 2018

UT engineers develop first method for controlling nanomotors: Breakthrough for nanotechnology as UT engineers develop first method for switching the mechanical motion of nanomotors September 21st, 2018

Nanobiotix: Update on Head and Neck Phase I/II Trial with NBTXR3 and Other program data presented at ImmunoRad 2018 September 20th, 2018

Research partnerships

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Leti & EFI Aim to Dramatically Improve Reliability & Speed of Low-Cost Electronic Devices for Autos: Project Will Extend Model Predictive Control Technique to Microcontrollers, Digital Signal Processors and Other Devices that Lack Powerful Computation Capabilities September 18th, 2018

Tiny camera lens may help link quantum computers to network September 14th, 2018

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project