Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Weak force has strong impact on nanosheets: Rice lab finds van der Waals force can deform nanoscale silver for optics, catalytic use

A transmission electron microscope image by Rice University scientists shows a silver nanoplate deformed by a particle, forming flower-shaped stress contours in the material that indicate a bump. Changing the shape of the material changes its electromagnetic properties, making it suitable for catalysis or optical applications. (Credit: The Jones Lab/Rice University)
A transmission electron microscope image by Rice University scientists shows a silver nanoplate deformed by a particle, forming flower-shaped stress contours in the material that indicate a bump. Changing the shape of the material changes its electromagnetic properties, making it suitable for catalysis or optical applications. (Credit: The Jones Lab/Rice University)

Abstract:
You have to look closely, but the hills are alive with the force of van der Walls.

Weak force has strong impact on nanosheets: Rice lab finds van der Waals force can deform nanoscale silver for optics, catalytic use

Houston, TX | Posted on December 15th, 2020

Rice University scientists found that nature’s ubiquitous “weak” force is sufficient to indent rigid nanosheets, extending their potential for use in nanoscale optics or catalytic systems.

Changing the shape of nanoscale particles changes their electromagnetic properties, said Matt Jones, the Norman and Gene Hackerman Assistant Professor of Chemistry and an assistant professor of materials science and nanoengineering. That makes the phenomenon worth further study.

“People care about particle shape, because the shape changes its optical properties,” Jones said. “This is a totally novel way of changing the shape of a particle.”

Jones and graduate student Sarah Rehn led the study in the American Chemical Society’s Nano Letters.

Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls.

“Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky,” Jones said. “When you put a large, flat particle on a large, flat surface, there’s a lot of contact, and it’s enough to permanently deform a particle that’s really thin and flexible.”

In the new study, the Rice team decided to see if the force could be used to manipulate 8-nanometer-thick sheets of ductile silver. After a mathematical model showed them it was possible, they placed 15-nanometer-wide iron oxide nanospheres on a surface and sprinkled prism-shaped nanosheets over them.

Without applying any other force, they saw through a transmission electron microscope that the nanosheets acquired permanent bumps where none existed before, right on top of the spheres. As measured, the distortions were about 10 times larger than the width of the spheres.

The hills weren’t very high, but simulations confirmed that van der Waals attraction between the sheet and the substrate surrounding the spheres was sufficient to influence the plasticity of the silver’s crystalline atomic lattice. They also showed that the same effect would occur in silicon dioxide and cadmium selenide nanosheets, and perhaps other compounds.

“We were trying to make really thin, large silver nanoplates and when we started taking images, we saw these strange, six-fold strain patterns, like flowers,” said Jones, who earned a multiyear Packard Fellowship in 2018 to develop advanced microscopy techniques.

“It didn’t make any sense, but we eventually figured out that it was a little ball of gunk that the plate was draped over, creating the strain,” he said. “We didn’t think anyone had investigated that, so we decided to have a look.

“What it comes down to is that when you make a particle really thin, it becomes really flexible, even if it’s a rigid metal,” Jones said.

In further experiments, the researchers saw nanospheres could be used to control the shape of the deformation, from single ridges when two spheres are close, to saddle shapes or isolated bumps when the spheres are farther apart.

They determined that sheets less than about 10 nanometers thick and with aspect ratios of about 100 are most amenable to deformation.

The researchers noted their technique creates “a new class of curvilinear structures based on substrate topography” that “would be difficult to generate lithographically.” That opens new possibilities for electromagnetic devices that are especially relevant to nanophotonic research.

Straining the silver lattice also turns the inert metal into a possible catalyst by creating defects where chemical reactions can happen.

“This gets exciting because now, most people make these kinds of metamaterials through lithography,” Jones said. “That’s a really powerful tool, but once you’ve used that to pattern your metal, you can never change it.

“Now we have the option, perhaps someday, to build a material that has one set of properties and then change it by deforming it,” he said. “Because the forces required to do so are so small, we hope to find a way to toggle between the two.”

Co-authors of the paper are graduate student Theodor Gerrard-Anderson, postdoctoral researchers Liang Qiao and Qing Zhu, and Geoff Wehmeyer, an assistant professor of mechanical engineering.

The Robert A. Welch Foundation, the David and Lucile Packard Foundation and the National Science Foundation supported the research.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,978 undergraduates and 3,192 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 1 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance.

Follow Rice News and Media Relations via Twitter @RiceUNews.

For more information, please click here

Contacts:
Jeff Falk
713-348-6775


Mike Williams
713-348-6728

Copyright © Rice University

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 Links

Read the abstract at:

The Jones Lab:

Department of Chemistry:

Department of Materials Science and NanoEngineering:

Related News Press

News and information

Study demonstrates that Ta2NiSe5 is not an excitonic insulator international research team settles the decade-long debate around the microscopic origin of symmetry breaking in the bulk crystal May 12th, 2023

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Novel design perovskite electrochemical cell for light-emission and light-detection May 12th, 2023

Govt.-Legislation/Regulation/Funding/Policy

Researchers at Purdue discover superconductive images are actually 3D and disorder-driven fractals May 12th, 2023

With new experimental method, researchers probe spin structure in 2D materials for first time: By observing spin structure in “magic-angle” graphene, a team of scientists led by Brown University researchers have found a workaround for a long-standing roadblock in the field of two May 12th, 2023

Optical switching at record speeds opens door for ultrafast, light-based electronics and computers: March 24th, 2023

Robot caterpillar demonstrates new approach to locomotion for soft robotics March 24th, 2023

Possible Futures

Researchers at Purdue discover superconductive images are actually 3D and disorder-driven fractals May 12th, 2023

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Novel design perovskite electrochemical cell for light-emission and light-detection May 12th, 2023

Optical computing/Photonic computing

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Optica Publishing Group announces launch of Optica Quantum: New, online-only Gold Open Access journal to rapidly disseminate high-impact research results across many sectors of quantum information science and technology May 12th, 2023

Efficient heat dissipation perovskite lasers using a high-thermal-conductivity diamond substrate April 14th, 2023

Discoveries

With new experimental method, researchers probe spin structure in 2D materials for first time: By observing spin structure in “magic-angle” graphene, a team of scientists led by Brown University researchers have found a workaround for a long-standing roadblock in the field of two May 12th, 2023

Study demonstrates that Ta2NiSe5 is not an excitonic insulator international research team settles the decade-long debate around the microscopic origin of symmetry breaking in the bulk crystal May 12th, 2023

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Materials/Metamaterials

Nanobiotechnology: How Nanomaterials Can Solve Biological and Medical Problems April 14th, 2023

New Developments in Biosensor Technology: From Nanomaterials to Cancer Detection April 14th, 2023

Diamond cut precision: University of Illinois to develop diamond sensors for neutron experiment and quantum information science April 14th, 2023

Graphene grows – and we can see it March 24th, 2023

Announcements

Study demonstrates that Ta2NiSe5 is not an excitonic insulator international research team settles the decade-long debate around the microscopic origin of symmetry breaking in the bulk crystal May 12th, 2023

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Novel design perovskite electrochemical cell for light-emission and light-detection May 12th, 2023

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Researchers at Purdue discover superconductive images are actually 3D and disorder-driven fractals May 12th, 2023

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Novel design perovskite electrochemical cell for light-emission and light-detection May 12th, 2023

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

Manchester graphene spin-out signs $1billion game-changing deal to help tackle global sustainability challenges: Landmark deal for the commercialisation of graphene April 14th, 2023

Optical switching at record speeds opens door for ultrafast, light-based electronics and computers: March 24th, 2023

Semiconductor lattice marries electrons and magnetic moments March 24th, 2023

Stanford researchers develop a new way to identify bacteria in fluids: An innovative adaptation of the technology in an old inkjet printer plus AI-assisted imaging leads to a faster, cheaper way to spot bacteria in blood, wastewater, and more March 3rd, 2023

Photonics/Optics/Lasers

Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023

Breakthrough in the optical properties of MXenes - two-dimensional heterostructures provide new ideas May 12th, 2023

Optica Publishing Group announces launch of Optica Quantum: New, online-only Gold Open Access journal to rapidly disseminate high-impact research results across many sectors of quantum information science and technology May 12th, 2023

Efficient heat dissipation perovskite lasers using a high-thermal-conductivity diamond substrate April 14th, 2023

Printing/Lithography/Inkjet/Inks/Bio-printing/Dyes

Disposable electronics on a simple sheet of paper October 7th, 2022

Newly developed technique to improve quantum dots color conversion performance: Researchers created perovskite quantum dot microarrays to achieve better results in full-color light-emitting devices and expand potential applications June 10th, 2022

On-Chip Photodetection: Two-dimensional material heterojunctions hetero-integration May 13th, 2022

With a zap of light, system switches objects' colors and patterns: "Programmable matter" technique could enable product designers to churn out prototypes with ease May 6th, 2021

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